Waterproof Hiking Daypack for the Big Adventures. HAJKER is a great waterproof adventure daypack, with a rolltop opening and plenty of smart storage solutions. The pack is made for high-speed activities and is equipped with our bounce free No Dancing Monkey™ 2.1 harness system and waist support belt that makes the pack stay put on your back without cramping your style. Zero bounce with No Dancing Monkey™ 2.0 and Snug Me - Harness developed and tested with top athletes to give you the perfect fit with no compromises, with absolutely no bounce. NDM Buckle - Technical buckle for a more secure closure and a better fit. 2-in-1 - The waist belt can be used on its own, perfect as a lightweight hip-pack for short rides. Waterproof - Rolltop opening to keep your gear safe from all kinds of weather.