The Retractaway Premium is a sleek metal handle offering the added safety of a hand retractable blade mechanism, Swann Morton Part number 2806.The main difference is the upgraded blade fitment to a stronger, more durable bayonet fit.Supplied in a sealed bag it is a highly versatile cutting tool produced with designers, graphic artists and model makers in mind. With easy blade changing it fits and safely retracts surgical blade No’s 10, 10A, 11, 15, 15A and 15C only.