"Product Description This Perforation Blade Kit is a direct replacement head for most 18"" electric creasing machines. Over time, the perf wheel gets dull and starts leaving messy or uneven tear lines. This kit restores clean, controlled perforation without buying a new machine. What's included: Blade Holder*1; Perforating Blade*1; White Rubber Wheel*1. Universal installation method: Holder Replacement: Loosen the screws on the back side of the holder to install the new holder. Blade Replacement: Loosen the black screw on the holder, take off the worn blade, insert the new blade, and re-tighten. Support Replacement: Loosen the shaft screws from both machine side plates, pull out the shaft, slide off the old support wheel, slide on the new one, then reinstall the shaft and tighten. This is a replacement accessory, not the full electric creasing machine. "