As you are buying this based on the single picture and the reviews it is hard to work out if it is worth it. I bought mine as I needed to attach my Garmin Nuvi 1310 to a scooter, although I had to attach it to the mirror stalk which with a lot more rubber pieces (that I had on me as these are not supplied) I managed to do. However the unit can not move very much so the viewing angle was a bit rubbish but I could still hear the voice so all was good.
The clamp part was different on mine, it has three teeth you can lever the clamp on to and screw it down, which I think is probably easier then what is shown. The unit can be detached and this is good but you do feel that the clip won't hold and will break after a few months.
The unit is splash and rain proof, although my unit did survive a 180 mile ride through heavy rain, although the vinyl screen did get a lot of condinsation which did limit the usefulness of the unit. I did turn off my unit when I saw this and it survived fine.
If you want to attach the a Sat Nav to the bike then it will work but make sure the clip is okay as the last thing you want is for your sat nav to fall off as you are doing 60mph down the road.