Four positions wire-connecting rail: 1.good quality 2.material:plastic 3.use for sauna heater,steamer,pool heater,etc. FOUR POSITION WIRE-CONNECTING RAIL1.small four positions2.material:plastic3.We have big and small two types for your choice4.use for sauna heater,steamer,pool heater,and etc.5.with good quality and durable big type Tel:+86763 3606018 Fax:+86763 3606000