The P5 is a very hot off-road glow plug from OS Engines. It is designed for OS enigines like 21VZ-B V-Spec and most .18-.28 off-road racing Turbo head engines. It is also used when the temperature is high or for leaner needle settings and high-nitro/high-rpm running.
Note: 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 head design.