1Pcs Blue 4Pcs Yellow: Material: Hard Alloy Product size: As shown Weight: About 120g Blade width: 1/8"-1/2" Diameter of handle of carving knife: 1/4 "; Usage: 6.35mm/0.25", 12.7mm/0.5" center shaft, used in electric and manual engraving machine. The 6.35mm/0.25" handle can be clamped by self-tightening to carve the machine and product 12pcs Yellow: Blade width: 6.35mm-32mm/0.25"-1.26" Diameter of handle of carving knife: 1/4" Usage: 6.35mm/0.25" center shaft, used in electric and manual engraving machine. The 6.35mm/0.25" handle can be clamped by self-tightening to carve the machine and product 12pcs Red: Cove Box Bit: 12.7mm Bearing Cove Box Bit: 22mm; Dovetail Bit: 12.7mm; Bearing 45° Chamfer Bit: 32mm; Bearing Flute Trim Bit: 12.7mm ; Straight Bit: 16mm; Rounding Over Bit: 22mm; Straight Bit: 12mm; Straight Bit: 6mm; Rounding Over Bit: 28.6mm; Grooving Bit: 12.7mm; Roman Ogee Bit: 25mm; 15pcs Red: Material: 45 # carbon steel, YG8 alloy Color: As picture shown Packing: wooden box Shank Diameter: 1/4":6.35mm/ 0.25" Wood Box Size: 1/4":17.3cm*12.4cm*5.1cm/ 6.8"*4.9"*2" (L*W*H) Included: 1/4/12/15 x Router Bits