Introducing the universal collar attachment for the High Tech MS-5 automatic pet door opener. The High Tech MS-5 Fastener has a flexible body to make insertion and removal of the MS-5 beacon easier which is double riveted to a Carbon Fiber Nylon Clip that comes in three available sizes 1.25, 1.5 and 2 inch widths. The J-Clip design fits over any type of collar including martingale designs. With the MS-5 Fastener you will never have to worry about the thin tab in the back of the MS-5 beacon breaking or having to do some heroics with zip ties to keep the MS-5 beacon on your pet. Our products are made in America and warrantied for life!