Fiskars 153180-1001 / 01-005318 Retractable Fingertip Knife. The blade of this ergonomic fingertip knife retracts for cap-free storage. To use, simply press the button to extend the knife. Insert your finger through the loop and let the natural motion and weight of your hand control your cutting. Features a bonus hang clip for convenient access. Uses standard standard type A #11 hobby knife blades.