This 4.5 Gallon Feeder has a large open top, and a solid one piece construction. Durable, UV protected. Comes with 3 Peach Teat brand nipples (pulls through the bucket) and 3 EZ Fit Adapters. Contoured edges and corners makes cleaning a breeze. Inside has a cutout so milk flows to the teat. This feeder is designed & proven to last for years. Back of Feeder has 2 durable metal brackets that have 2 adjustable positions. Mounts on a rail or fence.