1. With adjustable signal generator output, it is convenient to provide pulse signal to test circuit. 2. With buzzer, you can test the wire on and off (connect the wire to the power input and signal input, wire pass-buzzer sound) and low frequency signal (put the signal from the signal input, if there is signal, beep ). 3. The product is a spare part, it needs to be welded and assembled by itself, especially suitable for DIY. 4. DIY fans can be replaced with the same output 220V transformer, which can be used for AC 220V. 5. Suitable for DIY electronic production, adjustable power supply assembly. Plug Type:EU Plug,it applies to Indonesia, Germany, France, Spain, Italy and so on Voltage: AC220V Colour:Photo Color Material:ABS Package Contents: 1set x Adjustable regulated power supply (delivered as separate parts, different batches, different appearance and color, does not affect the use) 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.