Olfa RB451, 45mm. Rotary Blade Refill 1/pk. Circular rotary replacement blade for our popular 45mm rotary cutter used for quilting, sewing and general crafts. Cuts up to 6 layers of fabric. This blade features unparalleled sharpness and superior edge retention. For Original 60mm Rotary Cutter (RTY-2/G) and Deluxe 60mm Rotary Cutter (RTY-2/DX).