3 Sets Hair Clipper Replacement Blades Adjustable Clipper Blades 2 Hole (1mm - 3mm) Hair Trimmer Replacement Blades Compatible with Wahl 8148，8504，1919，2241，2240，8591 How to align the blades: 1. Move the blade adjustment lever to the full forward position. 2. Loosen the screws enough so the blades are still held in place, remove the screws. 3. Position the tips of the top blade teeth between 0.8-1.6 mm back from the bottom blade, so the blades cut too close or allow the moving blade to touch the skin. 4. Align bottom blade with the top blade, ensure that the extreme left hand tooth of top blade just on the first small tooth of the bottom blade, and the extreme right hand tooth of the top blade must be touching the big tooth on the bottom blade. 5. After blade is aligned, tighten the screws to hold the blades in place. 6. Turn switch on and off a couple of times, and then check alignment of blades. Applicable models: Wide compatibility: these 2 hole clipper replacement blades are compatible with Wahl 8148，8504，1919，2241，2240，8591，，Different from the size of screws, there are large screws and small screws, 8148,8504,2241,2240, both of which are small screws, 8591 and 1919 are large screws Specifications: Material: stainless steel Color: 2 silver and 1 gold Quantity: 3 sets (6 pieces) Package includes: 3 Sets of clipper replacement blades Note: Pointed items, please be careful when using and store them in places that away from kids. It is important to clean up immediately after each use and remember to replace the blade regularly. The mention of hair clipper's brand name and related model designation above is only applied for demonstrating product compatibility, not as a trademark. Our trademark is Mudder.