Leitz® Heavy Duty Staple Cartridges, up to 55 sheet cartridges, for use with Leitz® Heavy Duty Cartridge Stapler 0289225 Staple Cartridge Packs, over 1000 staples in each pack.This product features: * 55 sheets of 20 lb paper max capacity * Color coded cartridges match color key on stapler * 5 strips per pack * 210 staples per strip