A kite harness comes in seat (with leg loops), waist or vest types. The harness together with a spreader bar attaches the rider to the control bar. By hooking in, the harness takes most of the strain of the kite's pull off of the rider's arms, and spreads it across a portion of his body. This allows the rider to do jumps and other tricks while remaining attached to the kite via the control bar. Waist harnesses are by far the most popular harnesses among advanced riders, although seat harnesses make it possible to kitesurf with less effort from the rider and vest harnesses provide both flotation and impact protection. Kite harnesses look similar to windsurfing harnesses, but are actually much different; a windsurfing harness used for kiteboarding is likely to break very quickly, which could result in injury and/or gear loss. (source Wikipedia)