This automatic float box with Super Flow Valve and adjustable height mounting brackets features a stationary metal float box for watering troughs. Converts stock tanks, troughs, barrels and pans into automatic waterers. Easy to install...hook sturdy brackets over edge of trough and tighten thumb screws. The steel float mechanism has a tough, neoprene valve washer, that can be rotated and also reversed for long life. Plastic water float won’t rust. Longer float (greater leverage) allows up to 60 lbs. of water pressure. Works equally well on simple gravity systems. A larger valve opening increases capacity to 375 gallons per hour.