Achieving fluid motion takes more than counting ounces. The ultralight Optic 48 combines weight-saving design with exceptional fit and load management to give you a low base pack weight along with mileage-crushing efficiency. Comfortable carry and thoughtful trail features keep your head in the game so you stay ahead of your thru-hiking itinerary.AEROSPAN SUSPENSION: AeroSpan suspension with EVAP moisture wicking shallow-depth ventilated back panel.FOCUSFORM COMPONENTS: Ventilated, dual-density FocusForm shoulder harness and extra supportive hip belts with targeted comfort zones.LEAF-SPRING LUMBAR PAD: Leaf-Spring Lumbar pad for comfortable, energy-saving load transfer.INTERNAL ALUMINUM FRAME: Ultra-light 7001 aluminum perimeter frame with Anti-barreling support.CUSTOM FITTED RAINCOVER: Included rain cover stows in the top pocket for quick access in unexpected showers.REMOVABLE LID: Removable top zippered pocket to shed ounces and swap-in included ultra-light weather flap to stay protected (stows in top pocket).SUNGLASS QUICKSTOW SYSTEM: Sunglass storage system on shoulder harness for quick, secure and scratch-free access to your shades without taking the pack off.QUICK ACCESS WATER BOTTLE POCKETS: On-the-go water bottle stow access on both the right and Left sides.FRONT STRETCH MESH POCKET: Oversized, durable front stretch mesh pocket for quick access organization.ZIPPERED HIP BELT POCKETS: Dual zippered hip belt pockets provide secure, easy to access storage.STRETCH MESH SIDE POCKETS: Dual stretch mesh side pockets with Large capacity for bottles, camp sandals, trekking poles.ADJUSTABLE ATTACHMENT LOOPS: Dual adjustable attachment loops and upper shock locks for trekking poles or ice axes.ULTRALIGHT COMPRESSION STRAPS: V-Compression system on side and bottom of bags.PASS-THROUGH POCKET: Lower side compression pass-through on side pocket for over/under option.GEAR LOOPS: Gear attachment points on top pocket and main body.