The Sweetwater UL 28L is an ultralight daypack in recycled nylon, weighing 822 g for 28 litres — about 29.4 g per litre. Running-vest-style shoulder straps and an adjustable suspension system carry the load across the chest and let the fit be tuned to torso length, rather than relying on a single fixed strap position.
At 28 litres it's sized for day hiking: enough room for water, food, layers and basic safety gear for a single day out, not a multi-day load. No hip belt, frame or pocket layout details are given here beyond the strap and suspension system, so if those matter for your trip, check the current product listing.
It suits day hikers who want a lighter alternative to a full trekking pack with a more supportive fit than a basic frameless daypack.