Otter Creek Arms M4 Locating Collar, Black - Secure and Precise Collar for M4 Systems - OCL-201

Otter Creek Labs M4 Collar Black Nitride Finish Black. Made from H900 heat treated 17-4 steel. Specifications for Otter Creek Labs M4 Collar: Manufacturer: Otter Creek Labs Fabric/Material: 17-4 H900 Stainless Steel Gun Make: AR Platform Gun Model: M4 Weight: 0.1 lb Package Contents: Otter Creek Labs M4 Collar What firearm models does the manufacturer say Otter Creek Labs M4 Collar is compatible with? The manufacturer says that Otter Creek Labs M4 Collar is compatible with M4Otter Creek Labs OCL-201: M4 Collar Black Nitride Finish Black