The Hyperlite Mountain Gear Halka 55 is a 55-litre high-altitude mountaineering pack built from Dyneema Composite Fabric, weighing 1234 g with a rated maximum load of 22.68 kg. That's a demanding weight-to-capacity target even by ultralight standards, achieved through the waterproof, non-stretch DCF fabric rather than heavier nylon.
The internal vertical daisy chain for securing a single oxygen bottle (straps not included) and external attachment for ice tools and crampons mark this out as purpose-built for technical high-altitude routes rather than general backpacking — features most trekking packs don't need and don't include. Access is via drawstring closure, with a removable lid for further weight savings on summit pushes, and a daisy chain lets you lash extra gear to the outside. At 22.4 g per litre it's light for its rated load capacity, but the minimal internal structure and DCF fabric mean it rewards careful, expedition-style packing rather than the casual loading a padded trekking pack tolerates.