Due to customer demand for a way to use the popular SERPA Retention Holster as a shoulder rig, we have developed this comfortable shoulder harness platform. Made with a tapered web harness that adjusts for size and an offside dual Picatinny Rail Platform for any of our Picatinny Rail System accessories. Mount your SERPA holster on the underarm platform in a horizontal position. Secure carry and natural drawing motion. Enables one-handed reholstering. Made for both medium and large framed torsos.