These hair trimmer replacement blades are made of metal, featuring corrosion resistance and wear resistance for long-lasting use. The blades maintain sharpness, providing a sturdy and reliable performance over time. Each replacement blade is designed with 2 holes for convenient and secure installation, offering a cleaner and more stable hair cutting experience. The design allows smooth operation and effective cutting through various hair types. These adjustable clipper blades are compatible with models 8148, 8591, 8504, 2241, and 2240. Replace the blades as needed without purchasing a new clipper. With proper installation, performance is comparable to a new unit. To install, move the adjustable lever to the full forward position. Place the small top blade over the clipper drive finger, then position the large bottom blade on top. Use screws to partially tighten, ensuring the far left tooth of the top blade aligns with the first small tooth of the bottom blade. Fully tighten the screws once aligned. Test by turning the clipper on and off several times to confirm proper alignment. Note: screws are not included. Color: Black Material: Metal Package Contents: 1 x Large blade 1 x Small blade Note: The package includes only the items listed. Lighting and display differences may cause slight color variations between the image and the actual item. Measurement may vary by +/- 1-3 cm.