The School Smart 3-hole heavy duty punch is a quality classroom hole puncher that can punch up to 40 sheets of 16 lb paper at a time. Fully adjustable the 3-hole puncher features a neutralizing center head and easily converts from 3 to 2-hole punch when needed. (Please Note: To minimize shipping size and protect the paper punch arm this item is shipped with a black piece that locks the arm down. It is removed by pressing down on the arm and pulling the piece out.)