The SideWinder3 Self Retracting Lifeline (SRL's) are designed to arrest a fall when a worker falls off a leading edge. They can be used on a flat roof, sloped roof or in a vertical (overhead) position. SRL's are a very specialized piece of fall protection equipment and require user training in order to be used properly. Our SideWinder3 SRL's are offered in either 20 ft or 30 ft lengths and feature a strong Aluminum casing with stainless steel covers. All Sidewinders come with a 3600-pound gate steel twist lock carabiner to connect to your anchor point.