Ultimate Competition Series Blade Sets from Wahl offer high performance and long-lasting durability. Provide exceptional feeding of hair yet protect from cutting and jabbing. Feature distinctive silky, shiny black chrome finish for superior rust protection. 100% quality guaranteed to cut the first time. Fit Wahl Switchblade, Storm, KM2 and most Andis and Oster detachable clippers. Made in the USA.Size 40 - Surgical, 3/128", 0.6mm.