The Lutsen Series packs offer a large capacity and innovative Re-Fit air current suspension system that boasts a Re-Fit fully adjustable torso length and a Re-Fit fully adjustable hip belt So go ahead get a custom fit The Lutsen 45 and 55 are just the right size for going fast and light Traditional top loading design with a roll top closure and lidRATED BEST IN CLASS BY THE GEAR INSTITUTECapacity 2745 cu in45 LWeight 3 lbsTorso Length LGXL 18-22 inches