Feature:1. High quality material: made of high hardness carbon steel, square hole drill bit is solid, High quality.2. Excellent craft: each, went through CNC process, has smooth surface for less friction, sharp tip for better work.3. Good design: U-shape groove is great for the discharge of wood chips, to improve the drilling efficiency.4. Various dill bits: the set contains different size drill bits, enough, satisfied for multiple demands.5. Wide application: it works with mortising machine, very suitable for drilling wood, like MDF, particle board, pine wood, basswood, etc.Specification:Features:High quality material:made of high hardness carbon steel, square hole drill bit is solid, High quality.Excellent craft:each, went through CNC process, has smooth surface for less friction, sharp tip for better work.Good design:U-shape groove is great for the discharge of wood chips, to improve the drilling efficiency.Various dill bits:the set contains different size drill bits, enough, satisfied for multiple demands.Wide application:it works with mortising machine, very suitable for drilling wood, like MDF, particle board, pine wood, basswood, etc. Total 5 Combinations for Option4pcs: 1/4 inch (6.4mm), 5/16 inch (8mm), 3/8 inch (9.5mm), 1/2 inch (12.7mm)5pcs: 1/4 inch (6.4mm), 5/16 inch (8mm), 3/8 inch (9.5mm), 1/2 inch (12.7mm), 5/8 inch (16mm)6pcs: 1/4 inch (6.4mm), 5/16 inch (8mm), 3/8 inch (9.5mm), 1/2 inch (12.7mm), 9/16 inch (14mm), 5/8 inch (16mm)7pcs: 1/4 inch(6mm), 1/4 inch (6.4mm), 5/16 inch (8mm), 3/8 inch (9.5mm), 2/5 inch (10 mm), 1/2 inch (12.5mm), 1/2 inch (12.7mm)7pcs: 1/4 inch (6.4mm), 5/16 inch (8mm), 3/8 inch (9.5mm), 2/5 inch (10 mm), 1/2 inch (12.7mm), 9/16 inch (14mm), 5/8 inch (16mm)Specification:Material: Carbon SteelColor: SilverType: 4pcs / 5pcs / 6pcs / 7pcs / 7pcs (Optional)Package Size: 4pcs: 22*11*3cm / 8.66*4.33*1.18in5pcs: 22*13*3cm / 8.66*5.11*1.18in6pcs: 22.5*8.5*5.5cm / 8.85*3.34*2.16in7pcs: 22*13*5.5cm / 8.66*5.11*2.16in7pcs: 22.5*13*5.5cm / 8.85*5.11*2.16inPackage Weight: 4pcs: 670g / 23.63oz5pcs: 910g / 32.09oz6pcs: 1140g / 40.21oz7pcs: 1144g / 40.35oz7pcs: 1300g / 45.85ozNote:Drill bits set only, other accessories in the pictures are not included.The bit is not suitable for processing metal, , plastic, concrete, gypsum board etc.Due to lighting or other reasons, the picture and material object may slightly differ.Due to manual measurement, there may be deviation, please in kind prevail.Packing List:7 * Drill BitPackage List:7 * Drill Bit