1 . Hot SparkGlow Plug is suitable for T- 3.3, , VOLCANO , S30, VOLCANO S30, 21, HURRICANE XL, 3.0, 3.5, Glow Plug #4 fits for BACKDRAFT 3.5, CALDERA 3.0, EARTHQUAKE 3.0, EARTHQUAKE 3.5, HURRICANE XP, LANDSLIDE 21, LANDSLIDE , MONSOON XP, SANDSTORM 21 . 2 . Hot SparkGlow Plug is for RC Nitro Engines Car Truck , Glow Plug improves idle and transition. 3 . Hot SparkGlow Plug is for 4c Engines 5% - 40% Nitro Fuels, Spark Medium Hot Nitro Engine Parts behave very well on RC cars. 4 . Hot Glow Plug is made of Metal, Spark Medium Hot Nitro Engine Parts are of high quality. Colour:As Shown Material:Metal type:N4 Package Contents: 12 x RC Car Glow Plug Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.