This 31 piece set is for the ultra small screws found in electronics. The kit consists of 9 metric screw cutting dies: 1.0, 1.1, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2 & 2.5mm types in high speed steel and 18 equivalent taps in the same sizes above but with a taper and a plug version of the tap. There are 2 die liners to accommodate the smaller dies in the stock supplied. You will love this rare product. Supplied in a see-through plastic case which securely holds all parts.