We have to admit that we were very sceptical about this until we tried it.
Our concern was whether something so elegant could really crack all different sizes and types of nuts. So we put it on test in the kitchen, which turns out to be a high traffic area for nut eaters. Apart from the fact that no-one clears up their spent shells; the device was a complete success.
The brilliant thing about this design is that by turning a normal pivoted cracker upside down in a dish all the debris and detritus is collected, rather scattered all over the carpet or table linen. The device can be easily disassembled for cleaning and storage.