Plastic housing. General Purpose Relay can adjust automatically, protect and transform the electric circ. Wiring description: 1,8, the coil voltage contact of the relay; 2, 7,normally open contacts; 4,5,normally closed contact; 3,6, public points; There is a wiring diagram on the product. Wiring description For example: 2,3,4 This contact, 3 and 2 are normally open, 3 and 4 are normally closed. 8 Terminals, 2PDT 2NO 2NC type Total Size (Approx. ): 1. 4" x 1. 4" x 2. 6"/ 3.4 x 3.4 x 6.7cm; Socket Size: 2. 2" x 1. 6" x 0. 86"/ 5. 5 x 4 x 2. 1cm; It is perfect used in the remote control, communication, automatic control system, electronic equipment's... Package : 1 x Power Relay & Plug-in Terminal Socket Note:This power delay Warranty 1 year . We will be pleasure to exchange new one If there are any problems .