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_12VProduct series: RS232Rated current: 10ARated voltage: DC12V3C rated voltage range: below 36VRelay load current: Maximum 10ARelay load voltage: DC 1-100v or AC85-265vWeight: 67gSize: 8.5 x 4.7 x 1.8cm/3.35 x 1.85 x 0.71inchPackage Included:1 x RS232 Relay 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..