The OLFA Fabric Cutting Kit comprises of a 45mm Quick-Change Rotary Cutter and a 12in x 18in Double-sided, Self-Healing Rotary Mat. It is highly recommended to use OLFA self-healing rotary cutting mats to protect your workspace from damage and to prolong the lifespan of your blades. The Quick-Change Rotary Cutter (45mm) is designed for use with OLFA 45mm replacement blades, allowing you to effortlessly cut through up to 8 layers of cotton fabric.