This is the LWS Slinglok. This product allows you to secure your sling to your rifle and not have it flopping around to snag on objects. We have been field testing this product for a while now and we believe that it will provide an effecient/reliable solution to securing your sling. The Slinglok is covered by a limited lifetime warranty. If you can destroy it we will send you a new one. For installation please visit the following link -LWS Slinglok installation video-*Slinglok will not work on rail with vent cuts on the top rail such as Geissele rails or similar. There needs to be at least 2 valleys of the pic rail that are non modified so the set screws can sandwich the shock cord.