Optocoupler Tester Kit 555 Application Circuit Board Practice Welding DIY Electronic Spare Parts Kit Without DC Cable Optocouplers, also known as optocouplers, are commonly used electronic components that are difficult to test with ordinary instruments._x000D_ If a optocoupler with quality issues is installed in the circuit, it will cause the circuit to not work properly and it will be troublesome to replace it. Using this circuit, insert the optocoupler into the test stand, and after powering on, the LED flashes to indicate that the optocoupler is in good condition. Product Name:Optocoupler Tester Kit_x000D_ Working voltage:DC5V_x000D_ Note:Due to different production batches, electronic components may be different, which does not affect use._x000D_ Type:A:Without DC Cable_x000D_ Colour:Green_x000D_ Material:PCB+electronic components_x000D_ Size:Circuit board size:45x40mm Package Contents:_x000D_ 1 * Optocoupler Tester DIY Kit(This is a DIY kit, not a finished product) Only the above package content, other products are not included._x000D_ Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm. _x000D_ _x000D_ _x000D_ _x000D_ _x000D_ _x000D_ _x000D_