Narrow crown and wide crown staples

Parts of a staple:

There are 3 important measurements on a staple; the crown, the leg and the wire dimension. The wider the crown and the thicker the wire, the more secure the fastening will be.

The holding power of a cliched staple is dependent on all these measurements.

Note: Before you buy always check the minimum and maximum length of the fasteners that fit in your tool (mentioned in the tool owner's manual)