The OLFA CKB-2 contains two blades compatible with the NITECORE NTK10 utility knife and the OLFA CK-2. These razor-sharp blades are made from high quality stainless steel, making them strong and durable. Need to replace a blade while on the go? The included plastic storage case makes carrying replacement blades easy while the simple design of the OLFA CKB-2 ensures quick removal and installation.