Black Diamond stoppers are a good choice for a set of wires. Whilst perhaps not quite as popular as Wild Country Rocks or DMM Wallnuts they do provide a good alternative, or especially as a second climbing nut set. This is due in part to their considerably different shape in that they are fatter and squarer, meaning that you can cover more options for potential gear placements.
The nuts are anodized to aid quick gear selection. Most sizes have a transverse taper that permits sideways placements in flares and shallow seams, the smallest of sizes are straighter for better surface contact. The rounded edges reduce the chances of the nut snagging, making it easy to clean the route. All the stoppers have a durable galvanized steel cable which offers enough rigidity for above head placements, without the nut flopping around.
With the full range of Stoppers you end up with plenty of smaller wires due to their sizing (Roughly a Black Diamond Stopper 5 is equivalent to a size 2 Rock/Wallnut).
Durable aluminum heads and steel cables
Transverse taper is versatile in flares, constrictions and parallel cracks (smaller sizes are straight for better surface contact)
Rounded edges for easy cleaning