The O.S. LC4 T-Maxx/Revo Plug Medium Glow Plug is ideal for 1/10 scale off road engines such as the Traxxas TRX2.5 and 3.3T engines and the O.S. .21 TMs. It\'s platinum-alloy coil holds heat without an idle bar and reduces heat-related failures. Like all O.S. Max glow plugs, the LC4 is tough enough to take the heat and provide hassle-free starts an..