Osborne Oblong Crew Punch 19mm 3/4"

This is a top quality Osborne brand oblong / crew punch, manufactured in New Jersey, USA.

It is used to make a long slot shaped hole to fit a buckle onto a strap.  

This one makes a hole that is 20mm long from end to end and 3.3mm across the width.  You can also use this tool to make a longer slot by moving it along slightly and hitting it again.

This punch is used with a mallet, and with a nylon board underneath to protect the cutting edge of your tool.