Simple, subtle and secure. Emerging from the birth of the clean climbing era and decades of nut design (Stoppers, Hexes) Frost has reintroduced the straight sided tapered SENTINEL NUT. Key to both its holding power and cleaning ease are the relatively long faces which provide greater surface area contact without the "hang ups" inherent in curved nut designs. Almost invisible is an endwise taper which will seat nicely in moderate flares and pin scars. SENTINELS size grading allows 3 nuts to cover the range normally requiring 4. Available with either 8" or 12" stainless steel wire slings for aid, mixed and free climbing - save a quick draw & biner. Color coded.