Product DescriptionIngersoll Rand model 9512 Quick Change Retainer for . 401 Shank Chisels. Fits Ingersoll Rand pneumatic hammer models: 121, 132 and 772. This quick change hammer coupler holds 0.401 shank chisels in place, simply install the chisel by pulling back the collar.From the ManufacturerThe Ingersoll Rand 9512 Quick Change Retainer will fit on almost all maintenance air hammers - ours as well as our competitors.