Brilliantly designed small curved wires for thin cracks up to larger than finger-sized. Probably the most popular wires in the world - certainly the most popular in the UK - and with good reason. They seat well and can be placed in four different ways, presenting slightly different shapes so are almost certain to fit well if you've selected the right size. And the size range is just right.
The design is colour-coded for ease of recognition, but there is more to it than that. Each nut has been redesigned with the taper in the opposite direction. While not affecting the use of the nut, it means the larger sizes are up to 10g lighter than before.
Most climbers would carry two or three of each of these sizes up to Size 7, maybe a couple apiece of size 8 and 9, and one Size 10, though some of these might well be DMM Wallnuts which are almost identical in sizing but slightly different in design so offering further placement possibilities.
Whether you carry sizes 11 and upwards is a matter of individual preference. Size 14 is a bit of a monster!
These are the best nuts to start a rack with. Initially we would suggest buying a set of 1 - 8 plus a size 9.