Ordered 2 one worked great one didn't work. But they sent me a new one and now both work great! Nice to be able to lower the flow.

great for lowering the power of the rw8 which was to strong for my tank but still allows me to keep the rw8 if I should ever wish to upgrade. I must add that it is VERY silent in its operation.

Do a verry good job if you have to mucth power with WP pump !

Ottimo per regolare la potenza delle pompe jebao a piacimento

It is a great commodity.
I recommend!

I really like this unit! I can control my wp-40 with it. I don't use the night sensor on the pump, I found just turning the volume on the pump makes the red light come on, so adjusting the voltage slightly solves this. I am generally around 19 volts

Easy to install, work perfectly.
no noise in W1 set to 20 V

Very convenient for adjustment. You can select the required power.

This power supply is an excellent solution to reduce speed and also noise for the WP jebao pump. I adjusted it to 18V for my WP10 and it work perfectly for the size of my tank.

I ordered two WP-40 pumps and they came with the standard power supply. In my opinion the pump with the standard power supply is noisy in wave modes. I purchased two of the adjustable power supplies, have them set at the 19 volt setting and my pumps are almost silent.
The adjustable power supply also reduces the output of the pump so if you have a smaller tank this will work for you.
Bottom line is if you are going to buy the WP-40 you should also buy the adjustable power supply.