Inspired by Patagonia ambassadors’ requests for a bigger climbing pack, the Patagonia Ascensionist Pack 55L is a streamlined and ultrafunctional gear hauler designed for long approaches, lightweight expeditions and full-on missions into the alpine. Patagonia designed the Ascensionist 55L pack with enough room to comfortably carry everything you need for an extended stay in the mountains, including climbing with you through every move of your multi-day route. Working directly in the field with our team of climbing ambassadors, we created the Ascensionist’s lean, dynamic shape, which carries loads close to your core for climbing precision and support. The clean, stay-out-of-the-way design starts with lightweight yet durable 100% recycled nylon ripstop fabric with a 100% recycled polyester lining, a polyurethane coating and a DWR (durable water repellent) finish for durability and weather protection. Dual aluminum stays offer lightweight support for even the heaviest loads and provide stability for shifting contents; they move and flex with your body to preserve your natural climbing motion. The long spindrift collar has a dual closure to allow the pack to expand or collapse depending upon the load you’re carrying. The Ascensionist’s exterior has an adjustable ice-axe carrying system that keeps the sharp tips of your tools covered, a removable lid with a zip-closing stash pocket for easy access to small items, and removable compression straps for gear stability and quick options when you need to stow additional equipment. Inside, a handy hanging pocket keeps your easily misplaced items right where you need them. Other features include a three-point, over-the-top rope-carrying system, a burly haul loop, an adjustable sternum strap to accommodate layering and removable hipbelt pads to lighten your load for the summit push. Features and Specifications Two aluminum stays offer lightweight support for the heaviest loads while still allowing the pack to flex with your body With a removable lid, removable aluminum stays and removable hipbelt pads you can customize the Ascensionist for different objectives Our adjustable ice axe‒carrying system keeps sharp ice tool tips covered; it accepts most tool shapes Designed with modular, removable compression straps to provide maximum gear-carrying versatility and load stability The internal hanging pocket keeps your small essentials organized and easily accessible The tall spindrift collar has a dual closure that allows the pack to expand or collapse, depending on the load The three-point, over-the-top rope-carrying system can be removed to further streamline the load Weight: 1,280 g (2 lbs 13 oz) Materials: Body: 5.8-oz 420-denier 100% recycled nylon ripstop. Collar: 2.2-oz 70-denier nylon ripstop with a silicone coating.  Lining: 3.3-oz 200-denier 100% recycled polyester. All with a polyurethane coating and a DWR (durable water repellent) finish for durability and water protection. Body fabric is certified as bluesign® approved. Measuring Your Torso To Determine Your Pack Size Take a couple of minutes to accurately measure sizing will yield the best fitting pack possible. Follow these 3 easy steps:1. Find the Iliac crest (the top of the hip bone)2. Find the C7 Vertebra (the largest bump at the base of your neck)3. Measure from the C7 down along the spine to where it intersects with the Iliac Crest. Use the table below to then determine your correct pack size. Patagonia Technical Backpack Sizing Table  Size Range Suit Torso Length Suit Waist Small / Medium 16"- 19" 28"- 36" Large / Extra Large 19"- 22" 32"- 42" Patagonia Ascensionist 55 Litre Climbing / Mountaineering Backpack