These hair trimmer alternative blades are manufactured from metallic material, which operate corrosion-resistant and wear-resistant, well matched for long-life use and can reside pointed, durable and dependable to be applied for decades Each piece of hair clipper substitute blade is designed with 2 holes, which makes it considerate and convenient to operate, brings you cleaner and additional safe hair slicing experience, also be utilized smoothly to gild via maximum hair varieties very easily Our adjustable hair clippers blades have compatibility with 8148, , 8591, 8504, 2241 and 2240, you might easily update the blades in line with your needs, and no use to make your intellect up a fresh clipper, with correct installation, it's going to paintings as efficiently as a brand new one Make the adjustable lever of the blade go to the complete ahead position, role the small top blade over the clipper strain finger, then position the bottom blade on peak of small top blade, use screws and partly tighten, preserve that the extreme left hand teeth of top blade is aligned to the 1st small tooth of backside blade, you then can tighten screws, you could swap several to make whether or not you have aligned blades; Note: the screws should not included colour: black Material: metal Package Contents: 1*big knife 1*small knife Only the above package content, various item aren't included. Note: Light and various reveals can cause the colour of the object in the picture a bit of varied from the real thing. The measurement allowed error is +/- 1-3cm.