Nattools is a well regarded and innovative manufacturer that produces tools at mid tier pricing. 

A unique offering from Nattools, a self aligning watch strap punch jig.

• The base fashions a sliding mechanism that centres the watch strap and holds it in place. 
• The number of individual punches on the punch holders is configurable. You could remove the top and bottom punch if you're looking to punch only three holes on the watch strap.
  
  Full set includes base and all sizes availiable:

  Round 1.2, round 1.5, round 1.8, round 2.0 and 
  oblong 2.3, oblong 2.4 and oblong 2.5.