Danalock Extender for recessed square deadbolt

The "extender" on my deadbolt was physically part of the lever so all I had was a female square receptacle inside my door. In order to attach a Danalock (danalock.com) I designed and print this "adapter", which fits snugly but so far works well.
You might want to test it out then get it re-printed in metal for longevity though!
I've also included the sketchup file for modifications.