1This is 4 Channel Relay Module 2DC 12V power supply (voltage range 9-13v) 3Standby current (all relays closed) 18MA, 1 channel relay open 50MA, 2 channel relays open 81MA, 3 channel relays open 110MA, 4 channel relays open 141MA 4RS232 DB9 female interface 5"Read", "open", "close", "Selflocking" , click, interlock 6 commands, can satisfy most of the industrial control Features: This is 4 Channel Relay Module. DC 12V power supply (voltage range 9-13v). Standby current (all relays closed) 18MA, 1 channel relay open 50MA, 2 channel relays open 81MA, 3 channel relays open 110MA, 4 channel relays open 141MA. RS232 DB9 female interface. "Read", "open", "close", "Self-locking" , click, interlock 6 commands, can satisfy most of the industrial control. Specifications: Model: CE039_12V Product series: RS232 Rated current: 10A Rated voltage: DC12V 3C rated voltage range: below 36V Relay load current: Maximum 10A Relay load voltage: DC 1-100v or AC85-265v Weight: 67g Size: 8.5 x 4.7 x 1.8cm/3.35 x 1.85 x 0.71inch Package Included: 1 x RS232 Relay Detail information: https://onedrive.live.com/redir?resid=3DFF9FAEE8435679 15927&authkey= AG1AzoSlnv7JM4g&ithint=file%2crar Demo video: http://v.youku.com/v_show/id_XMTQwNzQzNDY3Mg==.html Note:Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.