Gunson Colortune G4074 14mm Classic Engine Petrol Diagnostic Saver Tune-Up Plug

Gunson Colortune G4074 14mm Classic Engine Petrol Diagnostic Saver Tune-Up Plug Gunson Colortune G4074 14mm Classic Engine Petrol Diagnostic / Tuning Kit. Ideal for tuning classic cars. This colortune kit is a spark plug with a glass window that lets you watch combustion.