Team Associated have introduced the MyLaps Hybrid and RC4 Black Edition transponders. The Hybrid (2-wire) transponder is the same size and features many of the same specs as the RC4 transponder, but it is backwards compatible with older decoder boxes. This transponder does not support car ID numbers. It is compatible with all AMBrc2 decoder boxes and MyLaps RC3 and RC4 decoder boxes.

See: Team Associated  

The RC4 (3-wire) transponder is the latest in the line of transponders from MyLaps. The RC4 transponder supports car ID numbers so you can have the same transponder number in all your cars, with a different ID for each. The RC4 transponder also gives additional telemetry data such as voltage to the transponder and transponder temperature each time the loop is crossed. This transponder will only work on RC4 decoder boxes with version 4 firmware or higher. (Use the harness to wire the transponder directly to your battery so it reads the true voltage, not the BEC regulated voltage, when you cross the line.)