The brim doubles as the packing pouch: fold it in and the whole cap collapses into a disc small enough for a jacket pocket. It weighs 28g, carries a UPF 50+ rating from recycled fabric, and uses a cord-lock at the back (Parapack calls it INFINI-FIT) to adjust across a 36-62cm head-size range rather than relying on a fixed strap size. It’s $40 direct from Parapack.