The Rock Island Armory A-2 High Cap Magazine is a standard factory replacement magazine. This magazine is for either Full Size or Mid Size A-2 models chambered in 22TCM and holds 17 rounds of ammunition. It is made of steel and is made to Armscor/Rock Island Armory specifications and tolerances, using the same manufacturing and materials as the original equipment magazines, ensuring perfect fit and operation. Fits: Rock Island Armory Full Size A-2 1911 chambered in 22TCM.