NO.5 AA Glow Plug Igniter Starter Fits 7mm Glow Plugs Nitro Engine for RC Car Blue No Need to charge, just use standard AA Batteries (batteries not included). An essential guide for anyone with RC cars. Will fit all Models that use a Glow Plug that is 7mm (hex) in diameter from flat end to flat end. These are glow plugs that are used on Smartech and ACME models.