These replacement harnesses are designed to be used with the Medium Skillbuilders Full Support Swing Seat. When attached and used, the harnesses provide extra comfort and support. Need to only change one harness? Not a problem. This total replacement set allows you to change whichever harness(es) you need when you need. This is a set of three harnesses only - Swing is sold separately. Works on swing seats with or without the pommel. The three replacement straps are 90", 60" and 7". Comes complete with an illustrated instruction manual. The harnesses are easy to attach and easy to clean.