The vaude ultra hiker 15 daysack is an ultra lightweight and compact pack with a ventilated back system to offer you an excellent level of comfort making it ideal for exploring the great outdoors on your bike and on day hikes the ultra hiker weighs in at just under 500g making it one of the lightest technical bags in its class while this model offers a capacity of 15 litres across a well sized main compartment two mesh side pockets and two zipped pockets on the lid making it the perfect bag to g