Big Bike Parts launched its Wireless Tire Pressure Monitoring Systems (WTPMS) in 2008 and they have brought unparalleled convenience and safety to riding to literally thousands of motorcyclists. In order to accommodate motorcycles with limited clearance and riders that desire a more permanent installation, Big Bike Parts has a WTPMS with internal sensors. This internal sensor system performs the same as their screw on external sensors counterparts, but mount inside the rim. These sensors easily fit in value stem holes for both American Twins and Metrics. The fob size monitor can fit in your pocket and will beep and vibrate to warn you of pressure or temperatures outside of the selected ranges. Selectable low pressure range from 10-50 psi, selectable high pressure range from 21-60 psi, and selected temperature range from 104°-210°F. The sealed battery on these internal sensors should provide about 5-7 years of service life. Our G-Force technology extends battery life by automatically sleeping until a change occurs. The TireGardTM system with internal sensors fits valve stem holes from .327" to .453" as used on most Harley and Metric rims.