8 Channel DPDT Signal Relay Module Board, DC 12V Version.
RY12W-K high quality signal relays, LED indicator for each relay channel. Darlington transistors circuit driving relay, improve the reliability of action.
Pitch 3.81mm / 0.15" screw terminal block, wire range 26-16AWG, strip length 5mm / 0.2", Metric M2 slotted screw.
FR-4 fiber glass PCB, dual copper layers.
Dimensions: 72.5mm x 150mm ( L x W ).

Operating Voltage: DC 12V.
Input control signal voltage:
0V - 0.5Vdc, low level, relay not action.
2.5V - 24Vdc, high level, relay action.
Input control signal high level current:
2.5V: 0.1mA.
5V: 0.35mA.
12V: 1.1mA.
20V: 1.9mA

Relay Spec:
Relay Part Number: RY12W-K series.
Contact Material: Gold Overlay Silver-Palladium.
Contact Rating: 120VAC / 0.5A, 24VDC / 1A.

Wire connection and PCB size:
VCC: Power supply input.
GND: Power supply ground and control signal ground.
IN-X: Control signal input, Low: relay not action, High: relay action.
COM / NO / NC:
Control signal state low, the relay OFF, COM - NO disconnected, COM - NC connected.
Control signal stage high, the relay ON, COM - NO connected, COM - NC disconnected.

This is a very simple module board, no paper specifications, any questions, feel free to tell me.
Datasheet: https://images-na.ssl-images-amazon.com/images/I/A1vg1+5HA8L.pdf