TR2 Transponder Systems NEW! Designed to replace the X2, the TR2 is the newest, most innovative transponder designed exclusively for auto racing. Accurate and reliable, unit utilizes reliable hardware and easy subscription management via Bluetooth and the Speedhive app. Subscription allows free online access to driver's practice and race results via the Speedhive platform. Choose from direct power units, that are powered by the vehicle's battery, or traditional rechargeable system.