ER collet wrench from a metal laser

At my work, there is a lot of CNC machines there is this type of wrench and first not really knowing the name and having a wish for more of them as the often gets lost or you need more then one for losing and tightening. I design one I Fusion 360 from a picture with a miner design modification, just because, why not. 

We also have a 1500W metal laser there is making quick work making 10 of this wrench