Dive-Xtras three-point harness
To properly use an underwater thruster, you must have a crotch strap to provide an attachment point for your scooter's tow rope.
Many divers using a back plate system have a crotch strap, but these are almost universally constructed using a single two inch piece of webbing passed between the legs. It works well to keep your gear from shifting, but it can be uncomfortable when used as a thruster with a lot of thrust.
The three-point Dive Xtras crotch strap is designed to shift thrust stresses from the crotch area to the legs. This makes long-term use of a scooter much more comfortable. The strap also performs the same functions as a normal crotch strap and prevents your gear from moving excessively.
This strap can also be used for people whose diving equipment does not come with a crotch strap. If your equipment has a 2 inch waist strap, the harness can be installed directly there, otherwise it can be used with a belt similar to a weight belt.