Spark plug adapter / reducer,18mm to 14mm 3/4in reach, with compression rings (18mm + 14mm) RAW no plating. Plug sits in recess in adaptor for maximun height clearance under the tank. Shorter adaptor thread to position long reach plug electrode in flame path. 7/8 inch (22.22mm) AF. Does not fit Champion plugs which have a larger diameter body. Champions require a different adaptor BT-OF-SPA18-34-champion-ass
