Features WIDELY APPLICABLE: This hole opener set is suitable for opening operations on materials such as aluminum, steel, casting, wood, plastic, gypsum board, stainless steel, etc. M42 STEEL MATERIAL: Made of M42 as the material, welded by electron beam welding, and then quenched by vacuum high temperature, has strong strength, strong wear resistance, and excellent toughness. INCISIVE TEETH: The use of the hole saw kit has a low vibration, quick balance during opening, and more stable. EASY TO USE: Accurate opening, time saving and labor saving, durable, and smoothly chip removal. Help you complete the hole cutting efficiently! 4PCS: There are 4 pieces hole openers in the package that in 32mm, 38mm, 44mm, 54mm, different specifications to meet your different needs, use with confidence! Specification: Item Type: Hole Saw Kit Material: M42 Steel Specification of Hole Opener: Approx. 32mm / 1.3in, 38mm / 1.5in, 44mm / 1.7in, 54mm / 2.1in Package List:4 x Hole Saw 1 x Drill Bit  Package List 4 x Hole Saw 1 x Drill Bit