These are replacement insert modules for Glock pistols to be used in Ergo's MAST Modular Armorer STand System. Ergo's MAST modules for Glock can be clamped in a bench vise, bolted to the side of a bench, or inserted in the Ergo's MAST base to support your pistol for display, maintenance, cleaning, or storage. Small Frame Module holds double-stack Glock pistols chambered in 9mm, .357 SIG & .40 S&W Ergo MAST modules for Glock are made of rugged reinforced molded polymer, with two hardened stainless steel pins that lock the insert module into the base. Mfg: Ergo Grips
