Longer distances and winter temperatures require extra room. The Optic 58 gives you that additional capacity without compromising your ultralight priorities. Proper load management, moisturewicking ventilation, and intelligent features keep you comfortable and mentally balanced from sea level to the High Sierra, because efficient trail travel involves more than a weight claim.
AeroSpan is the ultralight evolution of the groundbreaking VaporSpan suspension, delivering the same combination of 360-degree moisture-wicking ventilation and tensioned perimeter frame load management while paying obsessive attention to weight reduction. Using body-mapping techniques to target friction and impact points allows Gregory to eliminate hotspots without excess padding. FocusForm shoulder harness and hipbelts and LifeSpan foam provides lightweight comfort that outlasts other weight-conscious cushioning materials.
Measuring the back length
Measure with a tape measure along the spine from the 7th cervical vertebrae (the spinous process is easy to feel from the outside at the lower end of the neck furrow) to the iliac crest (at the level of the upper bony hip structure). Measure two or three times to get an accurate result. If you are between two frame sizes, the smaller size is right for you.
XS = 36 cm - 41 cm
S = 41 cm - 46 cm
M = 46 cm - 51 cm
L = 51 cm - 56 cm