Otter Creek Arms Llc OCL-201 M4 Collar Black Nitride
https://www.tandktactical.com/shop/664533659038-otter-creek-arms-llc-ocl-201-m4-collar-black-nitride-42462
https://www.tandktactical.com/web/image/product.template/42462/image_1920?unique=f86855a
Locating collar for M4 spec barrels and ops inc 12th model, AEM5 and OCM5. Made from H900 heat treated 17-4 steel with a black nitride finish.
