Installs in 1911 Autos with little to no fitting. Drop-In model fits snug in most slides, accepts standard barrels with no reaming. Oversize model has smaller I.D. that can be fitted to exactly match the barrel. Mfg: Mgw SPECS: .701" (17.8mm) O.D. 4340 CM or 416 Stainless steel. Drop-In: .580" (14.7mm) I.D. Oversize: .575" (14.6mm) I.D.
