OS Engines LC4 T-Maxx/Revo Glow Plug, Medium Ideal for 1/10 scale off road engines such as the Traxxas TRX2.5 and 3.3T engines and the O.S. .21 TMs Platinum-alloy coil holds heat without an idle bar and reduces heat-related failures Provides hassle-free starts and outstanding durability Longer reach extends coil farther into the engine's combustion chamber improving combustion for better idling and good acceleration Includes one glow plug and one brass washer