Optocouplers, also known as optocouplers, are commonly used electronic components that are difficult to test with ordinary instruments. If a optocoupler with quality issues is installed in the circuit, it cause the circuit to not work properly and it 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 Working voltage:DC5V Note:Due to different production batches, electronic components may be different, which does not affect use. Type:B:with DC Cable Colour:Green Material:PCB+electronic components Size:Circuit board size:45x40mm Package Contents: 1 * Optocoupler Tester DIY Kit(This is a DIY kit, not a finished product) Only the above package content, other products are not included. 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.