Little Giant makes these waterers in 3, 5 and 7 gallon sizes. They revamped the lid design, incorporating an O-ring seal, several years ago since they often didn't seal well with the old flat rubber washer. I've installed 1" plastic valves in these two old olds. I don't have to open the tops now and I can fill them more quickly and with less hassel with a hose in the valve.