REPLACEMENT BELT X4/P3000 (GREY) **KEN ONION EDITION** Belt Size: 1 x 18 Fine grit belt for the WSKTS-KO Blade Grinding Attachment. Intended for honing knives. X4 is equivalent to P3000. Belts are 1 x 18 and only fit the Work Sharp Knife & Tool Sharpener | Ken Onion Edition Blade Grinding Attachment and the Work Sharp WS3000 Belt Sharpening System.