Mountaineering Gear
Crampons, Harness Set (Two Locking Carabiners, Rappel Device, Ascender (Jumar)), Mountaineering Axe, Climbing Helmet.
Sleeping bag
It can get quite cool at night at 5000 meters while being relatively warm in the lower valleys on approach to peaks and passes.  It’s a good idea to have a warm bag, be it synthetic or down. Down really is preferred in the long run, as very rarely is the risk of your bag getting soaked (down doesn’t work when wet) an issue.  Down also compresses smaller, and is lighter weight. -20 °c recommended.
Inflatable Sleeping Pad (optional extra)
Bringing an inflatable sleeping pad is a nice addition to our mattresses.  
Sleeping bag liner
A nice addition but not necessary.  Oil from your skin gets into the down of your bag over time, reducing its loft.  A liner prevents this and can add warmth to an older bag or one that is borderline not warm enough.
Backpack
A pack in the 35–45-liter size for 6000–6500-meter mountaineering, leaning towards the larger size if you carry extra camera gear.  A well-fitting hip belt transfers the load from your shoulders to your hips, and this is appreciated for longer days. It shouldn’t cause any painful spots on your hip bones or shoulders.  
Double Boots
The best double boots aren’t cheap and are well worth the investment if you are a mountaineer or aspire to be.  If this is a one-off trip for you, you can hire them in Mendoza.
Trekking Shoes/ Lightweight trekking boots
You’ll need a pair of shoes/boots to wear around town, on the trail, and when you aren’t ascending up and down the mountain. Get a comfortable pair.  
Thongs/Crocs/Sandals
You’ll need a pair of flip flops/sandals/thongs to change into around camp, and when you want to give your feet a break. Bring a pair. 
Socks
Good socks are as important as boots, and you’ll need three to four pairs. Bring one pair of heavier trekking socks and three pairs of lighter-weight trekking socks.
Down/synthetic jacket
You’ll appreciate the warmth of one at a higher altitude, and while on your climb.  Down or synthetic will suffice.
Rain jacket (Shell jacket)
A good rain jacket will be useful for windy days, the odd rain shower, or for an extra layer on chilly days (they do contain your body heat, so they are good over an insulating layer).  Do invest in a good one that has a waterproof rating.
Softshell pants/Rain pants
You’ll need a good pair of breathable windproof/weatherproof pants to put on for summit day, and for when it gets windy. 
Base layers
There are several weights in base layers, including silk-weight, lightweight, mid-weight, and expedition weight. For trekking, we like to have one lightweight bottom, two lightweight tops, one mid-weight top, and one expedition weight top.  It’s nice to have the lightweight top to change into when you get to camp, and the heavier top layers are great to thermo-regulate while on the trail.  
Fleece/down pants
Throwing these on (or fully changing into them) over your trekking pants in the mornings and evenings around camp makes things pleasant.  Fleece or down models work well.  This completes your layering system, with three tops (light-weight,mid-weight, expedition weight), and two bottoms (lightweight, fleece/ synthetic down pants).
Trekking shirt
We recommend a trekking shirt with a collar for the sun (it can be folded up), and that is of synthetic material.  Some trekkers wear a synthetic t-shirt, along with a buff or bandana (see below).
Trekking pants
An important part of your kit, you’ll wear these for most of your trip.  Invest in a good pair that is lightweight, breathable, and quick drying. Pants that have a built-in belt fit better under your pack hip belt and a climbing harness.
Underwear
Bring 3 to 4 pairs, you’ll have the chance to do some clothes washing on the trip.
Warm hat/Beanie
Nice for the evenings and early mornings, and can be good for windy summits and passes.
Trekking poles
You either use trekking poles or you don’t.  If you don’t already have them and have trekked before, then you probably don’t need them.  Trekking poles can be good if you need extra support for your knees and/or ankles, but many choose to not use them. A trekking pole for summit day is useful to many.
Sunglasses
Bring one pair with 100% UV protection and wraparound style (to protect your eyes from the sun’s reflection from snow).  Make sure they are dark enough to keep your eyes comfortable on the brightest day.  If you have an extra cheap pair, bring those as well in case you break or lose your first pair.
Gloves
Gloves will be useful for windy/cold summits, especially if you tend to “run” cold.  Do bring a pair of liner gloves and windproof mid-weight gloves. Glove types and recommendations:
liners:
Liner gloves aren’t built to last, usually, you’ll get one trek or expedition out of them. 

windproof:
A good pair with a leather palm is indispensable and what you will probably use the most in your three sets of gloves.
shell:
You need a pair of these.  A pair of ski gloves will work but best to get a pair that work well with your liner gloves. When it’s windy at 6000 meters it’s best to not expose bare hands to the elements.
Water Bottle / Hydration bladder
Most guides will recommend 3 liters of water a day, and we know that every “body” is unique, so we encourage you to bring what you need.  For water containers, we use Camelbaks, Nalgenes, and just plain old water bottles from the corner market.  The main point is that you drink each day, so do have a plan for how you will carry your water.  Many prefer to bring a water bottle and a thermos, in this way, they can have hot drinks or water throughout the day, or just fill their thermos with cool water for the hot days. It’s a good idea to bring mixed drink powder as well for your daily needs, as you will need extra bouts of salt and sugar in your hydration plan.  The more you drink, the better days you will have.  It’s better to drink a little every hour as opposed to drinking in the morning and evenings.  Your body absorbs fluid better with this practice.  The absolute best (and worst tasting) hydration powders are Oral Rehydration Salts (ORS).  Typically used for rehydrating after a bout of diarrhea, ORS is the ticket to maintaining the best hydration even on the longest trek and climb days. 
~Urination bottle
It’s a good idea to bring a wide-mouth bottle for the inconvenient need to answer the call of nature at night.  A plastic peanut or pickle jar works great and is far less expensive than a Nalgene.  Do bring one, you’ll appreciate it.
Headlamp/torch and an extra set of batteries
Bring a good headlamp for your trek.  It should be bright enough to use on the trail if we have a day that is longer than usual, an early start for a pass or climb, or for reading in your tent.  Our dining tents are lit with solar power, so they’re a good place to save battery life on your headlamp.  You’ll want to bring your headlamp with you on the trail for a “just in case” situation.
Towel
It helps to have a towel along for drying your feet after washing them at the end of the day, for bathing next to the river on hot afternoon days at camp, and for washing your face in the morning to start the day.  We provide warm water for all these “activities”.
Sunblock
Bring sunblock lotion for your body, and a “face” type sunblock for your face and lips. It’s good to have a lip balm as well, Banana Boat and Coppertone make great ones.  You’re better off bringing this from home.  We prefer the “stick” varieties to the lotion types for your face.  They stay on longer and are more effective than lotions.  UV rays at high altitudes are two times as strong as those at sea level, the more sunblock you can bring the better.
Moisturizer
Bring moisturizer for dry skin after several days in the mountains.  Even if you don’t normally use one, you will go on treks and climbs.  It’s dryer and harsher at high altitudes.
Sun hat
You want to have a good sun hat with you, preferably one that is light in color as it’s far cooler temperature-wise than a dark-colored one.  We use a sun hat with a bandana underneath to absorb sweat and to hang down and block the sun on your neck.
Bandana
A bandana has one thousand different uses (if not more).  Bring one to cover your neck and ears in “sheik” style.  Also, it is great to get wet at river crossings and cool off your head. 
Buff
A buff is a neck gaiter that is made of very thin fabric.  We don’t go into the mountains anymore without one.  They protect your skin from sun and wind.  You can find them now in Leh, Manali, and Kathmandu.
First aid
We carry a full medicine / first aid kit.  Bring any personal medication that you need, and let your guide know so they can assist if there could be an emergency.
Water Purification
We purify our own water morning and evening for you.  If you think you’ll drink more water than you’d prefer to carry in a day, then bring water purification tablets to purify mid-day bottles filled in a stream.  You’ll be able to top off your water bottles at our water filter station in the mornings and evenings but will need to “fend for yourself” while we are on the trail if you need extra water.  Purification tablets are relatively inexpensive and lightweight to carry.
Camera
You’ll want to have a camera to document your trip. Bring enough memory cards and an extra battery for your camera.  You’ll be able to charge our camera several times during the trek on our solar unit.
Gaiters
An excellent addition to your mountaineering kit.  Keep the snow out, keep your legs warmer, and protect your pants (and lessen the chance of a crampon snag on your pants).
Snacks
Bring snacks for in-between meals, and for longer climb days. You’ll appreciate having a snack even if you normally don’t snack between meals.  You will eat a lot more on the trip, put salt on food, and use more sugar in tea and coffee.  Your body burns a lot of fuel in the mountains, keeping warm, ascending and descending, carrying your pack.  If you normally don’t eat salt and sugar on your foods at home, we’ll encourage you to while on trek. You’ll acclimatize better when you are more hydrated. Do bring snack bars, and some drink powder for your water bottles and/or water bladder