I got the product this morning thursday (ordered it last friday evening), so I got it first class and very quick.
I was surprised of the good quality of the elements. Especially the air duster is impressive. I will use it also for cleaning my camara lenses, as it give a really good blow and it is made of good rubber, nothing plastic.
The main tool is the one for removing the back of some watches. If you have a watch which has some kind of little holes at the outside of the back of your watch than this is the tool you want. Otherwhise you need a cap remover (looks like a small butterknife).
There are some bits of different size to match the holes. Ii did needed to use some force as the back of my Casio watch has been closed for more than 15 years. It did the job perfect without scratching the watch.
I haven't used the tweezers or brush, but the quality is good. And everything is kept in a bag which can be closed.
I can recommend this product to everyone.