Keep your USB Sharpener performing at its best, with the PS12-USB replacement blade units. Compatible with the entire Rapesco PS12-USB range, the pack consists of 2 x standard 6-8mm and 1 x large 9-12mm replacement units. Changing the sharpening unit is quick and easy to do, simply push the blade upwards into the sharpener, removing it from its mounting, and pull outwards to remove. The sharpeners handy safety feature means that the blades will only operate when the cover is attached. The carbon steel blades are made from high quality materials.