I was sceptical at first but this thing is really amazing!  It removes the undercoat... keeps the cats cool and also prevent hairballs. I will try to get one mainly for my Nush . Her hair has all grown back now.

It is quite costly though.. .not sure if it is available locally... but shaving Nush and Mirko every 3 months will cost much more. 

The only problem is that a lot of hair flies off so it's a bit messy.

http://www.furminator.com/photosDemos.cfm