Features: ?Carbide tip with higher hardness (HRA93), higher hardness, greater strength, tip more sharper, cutting plotter lettering faster. ?30°,45°,60° design fits most of cutting plotter. Application: ?30 degree blades (yellow cap): Cutting very small font & intricate line-art logos.(eg: any thin vinyl) ?45 degree blades (red cap): Cutting general fonts, vinyl film.(eg: vinyl for traffic sign, flocks, etc.) ?60 degree blades (blue cap): Cut large fonts, thick materials for about 1mm. (eg: reflective material, masking tapes, etc.) Specifications: Blade size: 20mm*1mm(L*Dia) Holder Size: 52mm*11mm(L*Dia) Material: Tungsten steel(blade);Stainless steel(Arbor) Color: 30°(Blue),45°(Red),60°(Yellow);Each color was 6pcs Quantity: 18PCS Blades+1PC Holder Package Includes: 6 * 30 Degree Cutter Blade (Yellow) 6 * 45 Degree Cutter Blade (Red) 6 * 60 Degree Cutter Blade (Blue) 1 * Blade Holder Installation Method: Open the holder base and take out the blade, remove the blade cover and put the blade in to the blade hole (black side), Re-tighten the holder base and you can start using it. Attention Please: The holder base has been improved, installation does not require use of a spring, making it easier to operate.