A friend has the TireGard tire air pressure monitor on his ST1300 and likes it. The sensors screw on to the tire stem and the remote held in place with velcro, but I was told the remote is not waterproof? No wires, so it's an easy install. I've had the Smartire for over 4 years with no problems, but they are out of business. About 1 1/2 years ago, I installed Orange Electronics TPMS($100 each) on our car and truck. It's a nice unit, but they are now out of business and one sensor on each vehicle is dead already. The Doran units have been around for a while, which is good for replacement parts. The TPMS has given us a low pressure heads up on each vehicle, so we really like it.