This is a relay module with high performance, which is convenient and practical for users. Module Interface 1. DC #43;: DC power supply positive; 2. DC -: DC power supply module negative; 3. IN: Signal input terminal(support High/Low Level switch freely); 4. Normally open (NO): Relay normally open; 5. Common terminal (COM): Relay common; 6. Normally closed terminal (NC): relay normally closed terminal; Specifications: Type: 4-Channel Relay Voltage: DC 12V Output Capacity: within DC 30V 30A or AC 250V 30A Quiescent Current: 5mA Trigger Current: 5mA Module Size: 128 * 68 * 20mm Module Weight: 177g Package List: 1 * Relay ModuleNote: 1. Please allow 1-3 mm error due to manual measurement and 1-3g weight error make sure you don't mind before ordering. 2. Due to the lighting of the photos and the difference of monitors, the pictures may not reflect the actual color of the real item. Please make sure you don't mind before ordering, thank you! About Shipping: 1.please pay attention to your delivery address such as: name, street, house number, doorbell/email without name, etc. is correct, or the order will not be delivered correctly. 2.All items will be shipped within 3 business days after the payment is received. Most times you will receive them within 8-12 days then. The specific delivery time is depend on circumstances. 3.During the shopping process, if you have any questions, please feel free to consult us, we will reply you within 24 hours Hope you have a pleasant shopping experience!