I must explain firstly, that I am a great fan of Proxxon tools
There is not a lot to say really, it is well made and feels right in the hand. I have been using it for extended periods cleaning up an aluminium table and the bearings went in the handset. Probably taking it beyond its normal capability. I found that the actual handset bearings are formed from polythene tubing; a rather neat answer to a difficult problem. The same type which form the water supply on caravans. In the handset, the tubing forms what I can only describe as sacrificial bearings. When the running becomes rough, just cut two more pieces of tubing and replace.