Amazon.com : Martin Yale 525M Master Hole Punch, 11/32" Hole Diameter, Punches Through Up To 40 Sheets of 20-lb. Bond Paper, Comes With 5 Punch Heads and Accepts a Total of 7 :
Officemate Adjustable 2-7 Hole Punch. Includes 7 Punch Heads. Punches 5-11 Sheet Capacity, Black with Chrome Trim (90070) : Amazon.com.au: Home