Mineral feeders utilize a high density polyethylene flap to protect feed & minerals from UV rays. Most any animal is attracted to this feeder and readily learns to use it. Heavy-duty 41 inch diameter flap protected by rubber disk. Link pin allows flap to ride up when lifted by animal; this permits "give" and extends life of flap and feeder. High density polyethylene. Hindered amine light stabilizer, the most effective ultraviolet inhibitor. Holds three 50 lb. salt or mineral blocks, can accommodate larger blocks up to 12 inches square or 200 lbs. of loose supplement level-full. | Hutchison Western Pride of The Farm Mineral Feeder