The Cajun Bowfishing Roller Arrow Rest screws into the rest bushing in bow riser and easy to install and adjust. The roller rest increases arrow speeds up to 10 feet per second. The roller is made from rust-proof sturdy Delrin on a brass-threaded shaft. From the Manufacturer --------------------- Easy to install and adjust; Screws into rest bushing in bow riser; Increases arrow speed up to 10 fps; Roller of rust-proof sturdy Delrin on a brass threaded shaft. Model: ABF4400.