Panel size: about 138 x 56 mm Size between mounting holes: about 131 x 48 mm The module is triggered by high level with current of not less than 5mA. Due to the output capability of part of the 51 single-chip IO is weak, you need to pull or increase drive capacity circuits. 1. Adopting Songle relay, output contact capacity is 10A 250VAC, 10A 30VDC, easily used in home appliances or industrial. 2. 8 channels are high level. 3. Each relay has the contacts that are normally open and closed. 4. Safe to use. 5. Can be selected with a jumper relay and TTL common ground common ground or not. 6. With power indicator for each channel. 7. Equipped with relay coil to get diodes protection. 1 x 8-Channel Relay Module