I’ve been looking for a suitable drain cock for years and this one is the winner! I’m using this cock as a petrol tank drain valve on my 1950 MG-TD. Petrol in the US often contains ethanol which is detrimental to fuel tanks, particularly for vehicles kept in long term storage. Replacing the original drain plug with this cock will greatly improve my ability to drain off accumulated water or old petrol. Full disclosure - it has yet to be installed so I can’t definitely say it’s leak proof. However, I have performed a leak test with compressed air and yes, it passes with flying colors. .