Oatey 45801 Hercules Mega Bubble Leak Detector, 8-Ounce Detects even the smallest gas leaks. Produces large, blue, long-lasting bubbles. Clings, even to vertical surfaces. Non-toxic, non-corrosive formula. Detects even the smallest gas leaks; Produces large, blue, long-lasting bubbles Clings, even to vertical surfaces Non-toxic, non-corrosive formula