This is a surplus new pump housing for a Viking rotary pump. It is cast iron and has the following part number: 2-214-809-100 or 2214809100. After searching online, I found that it appears to be compatible with these pumps: K125, K4125, KK125, KK4125, K124A, K4124A, KK124A, KK4124A; however, I am not sure of that. You should make sure the housing part number is compatible with your pump model before purchasing.