Stock tank float valves automatic Use to convert tanks or barrels into automatic stock waterers. Requires little attention and keeps open tanks filled with freshwater. Adjustable to several heights. Install by hanging plated brackets over edge of tank. Designed to operate on pressure up t o 70 PSI or from gravity flow with optional special orifice. Outer housing molded of high impact resin. Withstands weather and abuse. Durable molded float. Two sets of brackets. Fits poly tanks and steel tanks. 300 GPH.