The 1A3 tachometer sending unit is designed to screw into the engine's mechancial tachometer port (Lycoming/Continental style). Included is a 0.156 diameter tang along with a six-foot harness. Franklin engines require a different tang. The 1A3 TSU is designed to work with UMA TSU tachometers only. This version (EDMO# 1A3C-2) has a Lycoming/Continental style connection.
