I ordered the first set of these straploks because I was using an older leather strap that had sentimental value but questionable post holes.  These things work so well and lock in so solidly that I now put a set on all my new instruments before I sling them over my shoulder.  I prefer the Dunlop push-button approach to the Schaeller pull-pin design.  And the fact that the strap rides above the post allows me to loop the guitar cord over the endpin without anything binding or rubbing against the guitar finish.  Highly recommended!