This insert is a blind threaded fastener that has a brass threaded insert molded into a neoprene bushing. You can install this insert into through holes or blind holes without tools of any kind. This fastener makes the joint waterproof, isolates vibration and is electrically insulated. The body of the insert is available in a large variety of sizes and styles with flange height and diameter being the most predominant consideration. The insert, made out of brass as the standard part, is available in sizes from 6-32 thru 3/8-16 and the equivalent metric sizes. EPDM inserts are available through special order. EPDM inserts are for use where exposure to UV rays or oil is probable.