What is the sliding Camstrap gadget?

[Ramsden]

Hi folks

Sorry if this seems a dumb question.  I  bought a camstrap about a year ago and really enjoy using it, but I cant figure out the sliding gadget that came with it. I've looked on line and no references to it - so I turn to my trusty friends across the pond!

 

 Thanks

Ramsden

[Ramsden]

Ignore this post  - i found it on line. Just a note - my lens caps are mainly plastic, so its not much use!