I purchased this SKROSS World Adapter MUV USB that allows you to charge 2 USB devices and connect something else like your laptop at the same time. Honestly, I thought I was purchasing something of premium quality. Unfortunately I didn’t, the noise this things makes just by plugging it to the wall it’s incredibly annoying.
I double checked in Amazon.com, just in case my unit came faulty and could find several people also complaining about exactly the same.
This is supposed to be a Swiss designed product. I live in Switzerland, so I know that Swiss stuff is usually of high quality. Unfortunately, this is an exception.
My suggestion, avoid this model, and check for other options. I hope they fix this as soon as possible!