These are made by the people who created this design which is power connections Harlow ,I think there are copies and even fakes available so be careful.

These are stamped with the kite mark and conform to BS5733 , please zoom in to the picture of the underside and you will see the relevant certification stamps.

We used these to convert goods bought in Europe to conform to UK sales requirements , the plugs are super easy to use , they simply fold round the 2 pin plug , screw up and are ready to go , they don't even look like a converter they just look look a 3 pin plug 

I will do listing for these at different price points 10 , 50 and 100 pcs

you are welcome to collect , any questions please feel free to ask