This is an excellent product - it is particularly good at shelling almonds and hazelnuts without breaking the nuts. It can cope fine with walnuts and brazil nuts as well, but they are more prone to being slightly crushed in the process. Some people have said walnuts are too big for it - they must be pretty huge walnuts, as all of mine have fit (although there is not a massive amount of spare headroom).
The best things about it are that it looks pretty industrial (nice if you like that sort of thing, which I do), and the crack from a particularly tough almond is surprisingly satisfying.