Mountainsmith Zerk 25 BackpackNEW SIZE! You asked for it, so we delivered! Designed as part of the growing Zerk Family, this fast and light pack is ideal for quick trips into the mountains when versatility and comfort are key. This pack is loaded with features and can be customized for all your backcountry needs. New updated version includes added daisy chain attachment points, dual ice axe loops, dual side compression straps, and embroidered design. 20" x 12" x 9" 1. 5 removable