This external ignition coil doesn't have a spark plug cap. The external ignition coil with a cap for the Honda TRX 90 Sportrax, TRX 90 X, XR 600 R and XR 650 L 1991-2016 models is RM06001. In CDI type coils, there is no polarity. You can hook it up any way. The green and black pins doesn't matter. (No ground-specific)Aftermarket replacement part for: Yamaha XC 125 -- 2004-2006Yamaha X-max 250 -- 2005-2006 Brand new aftermarket external ignition coil You must re-install your OEM spark plug cap(s) Once your OEM spark plug cap(s) are re-installed, our part becomes a Plug-and-play unit, direct fit, and easy to install All products shipped are tested This is a multifit part. For more details, please see our description. ASIN B07G8FHH9V Brand Name RMSTATOR Item Weight 0.12 Pounds Manufacturer RMSTATOR Model Number RM06025--SC--Y Item Dimensions 9.8 x 4 x 9.8 inches Installation Type Plug In Automotive Fit Type Vehicle Specific Fit Included Components External Ignition Coil Part Interchange Info replacement Manufacturer Part Number RM06025--SC--Y OEM Equivalent Part Number 1C0-H2310-00, 30510-GAG-000 Compatible with Vehicle Type Scooter Manufacturer Warranty Description 2 Years