These hair trimmer replacement blades are made from steel material, which characteristic corrosion-resistant and wear-resistant, right for long-life use and may live pointed, sturdy and reliable to be applied for decades Each piece of hair clipper replacement blade is designed with 2 holes, which makes it thoughtful and convenient to operate, brings you cleaner and extra safe hair reducing experience, even be applied smoothly to gild through most hair kinds conveniently Our adjustable hair clippers blades have compatibility with 8148, , 8591, 8504, 2241 and 2240, you may just update the blades in step together with your needs, and no use to make a decision a fresh clipper, with correct installation, it is going to paintings as efficiently as a brand new one Make the adjustable lever of the blade go to the total forward position, position the small peak blade over the clipper stress finger, then role the lowest blade on top of small height blade, use screws and partly tighten, hold that the intense left hand tooth of height blade is aligned to the 1st small teeth of backside blade, then you can tighten screws, you may change a number of to make whether or no longer you have aligned blades; Note: the screws aren't included colour: black Material: steel Package Contents: 1*big knife 1*small knife Only the above kit content, diverse merchandise will not be included. Note: Light and sundry reveals may cause the colour of the thing in the picture just a little different from the real thing. The length allowed error is +/- 1-3cm.