Features: Made of superior high speed steel, high hardness and anti-corrosion. Each tap extractor is specifically engineered for speedy grab-it and easy out broken screw taps. Works for removing stripped, rusted, broken, or corroded screws and bolts. Every tap extractor goes through rigorous quality testing, durable to use. Suitable for industrial screw and bolt removal and for everyday home repair work. Specification: Condition: brand new Material: High Speed Steel Weight & Model: (Optional) #A 108g/3.8oz (six-piece set) Specification Metric System British / AmericanSystem 1# M4 6# 2# M5 8-10# 3# M6 12#-1/4 4# M7-8 5/16" 5# M9-10 3/8" 6# M11-12 7/16-1/2" #B 493g/17.4oz (nine-piece set) Specification Metric System British / American System 2# M5 8-10# 3# M6 12#-1/4 4# M7-8 5/16" 5# M9-10 3/8" 6# M11-12 7/16-1/2" 7# M14 9/16" 8# M16 5/8" 9# M18-20 3/4" 10# M22-24 7/8-1" #C 656g/23.1oz (ten-piece set) Specification Metric System British / American System 1# M4 6# 2# M5 8-10# 3# M6 12#-1/4 4# M7-8 5/16" 5# M9-10 3/8" 6# M11-12 7/16-1/2" 7# M14 9/16" 8#