Quantity: a lot of 1 piece. This item has been assembled, and electrical test passed. LED indicator for each relay channel. 2N5551 transistor driving relay. FR-4 Fiber glass PCB (Dual Layer). Size: L80mm x W72mm x H22mm Power Supply: 48V DC / 40mA. Input control signal voltage: 0V - 0.5V Low stage (relay no action), 0.5V – 2.5V (unknown state). 2.5V - 24V High state (relay action). Input control signal high state current: 2.5V: 0.1mA. 5V: 0.35mA. 12V: 1.1mA. 24V: 2.2mA. Relay Spec: Contact Rating: 277 VAC / 10 Amp or 30 VDC/10 Amp. Part number: SRU-48VDC-SL-C. Terminal block characteristic: Wire range 26-12AWG Mechanical Torque 0.4Nm(3.5Lb-In.) Strip length 7mm Dimensions Pitch 5.0mm(.197") Screws M2.5 Wire connection and PCB size: VCC: Power supply input. GND: Power supply ground and control signal ground. INx: Control signal input, Low: relay no action, High: relay action. COM / NO / NC: (Cx = COMx) Control signal state low, the relay no action, COM - NO disconnected, COM - NC connected. Control signal stage high, the relay action, COM - NO connected, COM - NC disconnected.