Little Giant Trough-O-Matic Float Valves automatically control the water level for most plastic and metal stock tanks, troughs, barrels, and pans. Operates at pressure between 20 and 50 psi. Features a 245 gallon per hour capacity and accepts ¾” garden hose thread. Available in Plastic (TM825) and Metal (TM830). The TM825T (plastic) and TM830T (metal) are for wide tanks that include expansion brackets to fit tank rims up to 2 inches thick and 4 3/8 inches wide. The TM825AS (plastic) complies with basic back-siphoning regulations.