200 higher cutting speed long lasting higher flexibility comprehensive set in this set you will find all common holesaws all the diameters you could need are supplied in this set you will never have to say again oh that size is missing it cuts through iron steel not ferrous metals cast iron hard and soft wood plastic lightweight building blocks plasterboard etc contents 2 x mounting shanks with centring drill 1 x extension 14 x bimetal hole cutters 16 19 2