Ruger Stock Adapter, Fits Ruger American Rimfire, 10/22 and any Ruger rifle w/the Modular Stock System, Low Comb/Standard Pull, Black 90431 Ruger's Stock Module" Low Comb/Standard Length of Pull" fits Ruger American Rimfire" 10/22 and any other Ruger rifle with the Modular Stock System. 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. It has the standard length of pull. Genuine Ruger Factory Accessory. 1.26" Comb Height" 13.75" Length of Pull.