Product Parameters:
Relay Type 12V Dual Channel
TTL Gate Circuit - Static Current: 5mA
Maximum current: 80mA - Trigger current: 3 - 5mA
Trigger voltage (low): 0 - 4V 0 - 4V, trigger voltage (high): 4.5 - 12V
No Maximum Load: AC 250V, 10A or DC 30V, 10A
Power Indicator Green, Relay Status Indicator Red
Dimensions (L x W x H): 51*41*19 mm
Weight: 30 grams

Operating Instructions:
How to select high/low level trigger terminals
S1 is the high/low level trigger selector terminal for channel-1 relay.
S2 is the high/low level trigger selector terminal for channel-2 relay.
When the jumper (COM) and the high level pin are shorted, the high level trigger operates.
When the jumper (COM) and the low level pin are shorted, the low level trigger operates.
Input connector:
DC+ : Power positive (VCC, voltage = 12V)
DC-: Power negative (GND)
IN1: Channel-1 signaling trigger, control relay pickup by high/low level trigger
IN2: Channel-2 signaling trigger, picked up by a relay controlled by a high/low level trigger
Output Interface:
NO1: channel-1 relay connection in normally open state (relay switch is suspended before pickup, after pickup the switch will be connected to "COM1")
COM1: common interface for channel-1 relay switch
NC1: Normally closed state channel-1 relay connection (relay switch is connected to "COM1" before pickup, after pickup the switch is suspended)
NO2: Channel-2 relay connection in normally open state (pre-pickup relay switch is suspended, post-pickup switch is connected to "COM2").
COM2: common connection for channel-2 relay switch
NC2: normally closed channel-2 connection (pre-pickup relay switch is connected to "COM2", post-pickup switch will be dangling)

What you will receive:
2x 12V Dual Channel Relay Module