I do like this item but i don't know if i should have gone for the more expensive German make or if it's just me.
The instructions are very simple, put on top of the egg, pull up the knob and let go, it will be perfect every time. That's where i think the knack comes in because mine hasn't been perfect every time. It was perfect the first time, another time the egg exploded but more than not it seems to get stuck but doesn't quite take the top off, it just serates the top so if you just put your knife in it will come off without any little bits of shell which isn't how they promote it. I will not give up as i am quite close so i will keep practising.