Features: Adopt patch photocoupler isolation, strong driving ability, stable performance. Trigger current is 5mA. Each path of the module can be triggered by the high level or low level through a jumper setting. Fault-tolerant design,even if the control line breaks,the relay will not move. Power indicator light (green), 4-way relay state indicator light (red). Humanized interface design, all interfaces can be directly connected through the terminal lead, very convenient. Four fixing bolt holes are provided. Specification: Weight: 18g/0.6oz Module Size (L*W*H): 50*26*18.5mm/2*1*0.7inch Bolt Hole: 3.1 mm; 44.5*20.5mm (spacing) Module interface: 2. DC- : connect to the power negative pole. 3. IN: high or low level control relay suction Relay output terminal: 1. NO: relay changeover interface,relay suction front suspension, suction and COM short connection. 2.COM: Relay common interface. 3.NC: Relay normally closed interface,relay suction and COM short joint, suction clearance. High and low level trigger selection terminal: 1. When jumper is connected with LOW short circuit, it is triggered by LOW level; 2. High level is triggered when jumper is connected with high short circuit; Package List: 1 x Relay Module