This stock module kit contains one 1.26'' Comb, 13.75'' Length of Pull (item 90431). This comb is intended for use with standard iron sights. The low comb height allows for the ideal placement of the shooter's cheek, in line with the sights. The second comb is a 1.84'' Comb, 13.75'' Length of Pull (item 90432). This comb is intended for use with aftermarket scopes or mounted sights. The high comb height raises the shooter's cheek placement, putting the eyes in line with the mounted optics. Both combs have the standard length of pull buttstock, ideal for shooters that prefer a longer length of pull. Fits any RugerŪ rifle with the Modular Stock System.