This is a Fusion Pro-Series, High carbon steel extended slide stop for 1911 Colt style pistols, size for 9mm/38 Super/40 S&W & 10mm with Matte finish. Precision machined CNC from 4140 alloy steel Bar Stock & heat treated. Will work with all 1911 Colt style pistols, models and sizes. This is a super high grade Professional Gunsmithing part, with black oxide finish. Made in the USA.