Heavy Duty Blades, these blades are standard pattern blades and will fit Dolphin knives and most types of knife handles.Perfect for the carpet fitter and many other trades. Packed in 100 per plastic safety box. Made in Sheffield England. (please note: these are very sharp heavy duty blades specially honed for carpet fitting, you must be 18 or over to purchase this item & care must be taken when handling these blades.)