About this 3D model

I created these while putting together this http://www.thingiverse.com/thing:108494 phone holder. I only had the "make" piece in the car to work with so I measured it out, drew that up and then made the reverse piece as a small box so that I could do MANY MANY test prints and trials to get both pieces to work. I have plans to re-use this and realized it's a re-usable fairly commong part. I should share. They work. I use the phone holder every day, and it is perfectly snug on the key. Good luck.