Features 1、With two serial ports, RS232 DB9 interface and TTL232 interface 2、With AT instruction and 8-byte instruction, the two instructions are automatically recognized, no need to switch 3、6 working modes, open, close, jog, self-lock, interlock, delay (8-byte instruction without delay mode) 4、Maximum delay of 9999 seconds under AT command 5、Adopted of high quality electronic components, and accuracy process, ensure for the durability Specification Item Type: RS232 Delay Relay Module Working Voltage: DC 12V Working Current (DC 12V): Standby 16MA, 1 relay opens 47MA Two Types of Instructions: AT and 8-byte instructions. The two types of instructions are automatically recognized without switching. Two Serial Ports: RS232 DB9 interface, TTL 232 interface 6 Working Modes: Open, close, jog, self-lock, interlock, and delay (8-byte instruction without delay) Maximum delay of 9999 seconds under AT command Size: Approx. 56.5 x 31.5 x 17.5mm / 2.2 x 1.2 x 0.7in Maximum Load: 10A / 250VAC, 10A / 125VAC, 10A / 30VDC, 10A / 28VDC, 10A / 12VDC Package List 1 x RS232 Delay Relay Module