Streamlined for fast-moving treks and through-hikes, the Aircontact Ultra 45+5 SL delivers ultralight performance without sacrificing comfort. The SL fit is tailored for women, offering a secure, ergonomic carry even on technical routes. With the Aircontact Lite back system, an expandable 5-liter collar, and minimalist features, this pack keeps weight low and efficiency high for demanding days on the move. Lightweight where it matters most - and built to go far. Features Air Spacer Mesh - Back-friendly spacer fabric Round profile frame made of permanently elastic spring steel Clip & Loop back length adjustment Lumbar pad for effective load transfer Comfortable to wear thanks to movable, ergonomically shaped Active Fit shoulder straps with soft-edge finishes Load adjustment strap 2-way adjustable sternum strap ergonomic padded hip fins Pull-forward adjustment with automatic side compression snug hip fins Attachment loops modular gear straps Removal backpack lid Height adjustable lid Zippered lid compartment top-loader with roll-top closure extandable capacity (5L) Drinking system compartment Compatible with 3.0 liter drinking system/bag SOS label Safety whistle mesh side and front pockets Mesh helmet holder sold separately Materials D stands for denier. This describes the yarn weight. 600D corresponds to 600 grams per 9000 meters. * PES stands for polyester. PES fibres are very tear and abrasion resistant and hardly absorb moisture. * PA stands for polyamide. PA fibres are extremely durable and abrasion-resistant. They are also characterized by high elasticity and low weight.