Jack Wolfskin's Speed Liner Daypack carries just the basics for fast paced adventures on trails whether you're running or mountain biking. Its ACS Tight Lite suspension system has a close fitting design that still allows active ventilation and optimum freedom of movement. Waterproof Flex Shield works with durable yet lightweight Cross Rip fabric to ensure protection and comfort. The Speed Liner also features multiple pockets for complete organizational convenience. There's a hydration sleeve with a tube duct and attachment for your own reservoir. Stretchy straps accommodate most helmets, and the rain cover pulls out of the base compartment when wet weather threatens your gear. There are reflectors and an anchor for your own flashing light, too.