Function: Web servers allow access and control Relay via WEB Support status return to show current status of relay reset function with short press to reset, long press to return to factory settings. Supports 485 networks. Optocoupler to support internal circuit protection and prevent external voltage surges Specifications: Color: White, Black (Optional) Operating Voltage: 9V - 40V DC Load Capacity: 250V / AC 10A Size: 145 * 90 * 40mm / 5.7 * 3.54 * 1.57 inch Note: We recommend using an intrance instead of external control. Otherwise, the security may be lacking. Package Included: 1 x Controller Module 1 x Protective Cover