OS No6 (formerly A3) Short Standard Hot Glow Plug

OS No6 (formerly A3) Short Standard Hot Glow Plug OS-71605300 OS No6 (formerly A3) Short Standard Hot Glow Plug. A short bodied standard glow plug for use in small block engines and some aero engines. The hotter rating gives crisper idling, simpler tuning but offers a shorter life span when used under higher compression or leaner mixture settings. The No6 plus is what was previously known as the A3 glow plug from OS.