This is the O.S. T-Series RP6 Medium Heat Range Turbo Glow Plug.
T-series glow plugs are ideal for racing car engines that create high
For .12, .15 and .21 size turbo head on-road racing engines
Ideal plug for cool outside temperatures
O.S. T-Series RP6 Medium Heat Range Turbo Glow Plug
Glow Plug Wrench, HCAP2550
This glow plug is different from the conventional glow plug. It is
made to fit the inner head of engines with a turbo-type cylinder