I designed these tanks 14 yrs ago for the Yamaha Nytro snowmobile, known for oil tanks cracking, mounts breaking, tanks punctures an even worse engine failures. The tank that is on the YXZ's are the same model tank that is on the XX model wildcats, which are known for drain plugs stripping or even worse getting punctured. All  our HD oil tanks are built from .120 thick 5052 aluminum, internally baffled like stock tank, CNC fittings, fully tig welded and pressure tested. This tank come standard with 12mm drain plugs that will accept a quick drain, which is a must on the XX to make oil changes clean and easy. included is 12mm drain plug and  seal washer, I have sold hundreds of Nytro HD and  YXZ HD oil tanks with zero failures. Free Shipping to the lower 48 states, please contact me for shipping quote elsewhere.