This is a hex bit holder made specifically for Ryobi PSB1D01 impact driver. 

The bit forms a claw like insert that clips onto two of the impact driver's many vent hole. Holds on to the driver securely, I can pick up the driver from the bit holder.  It does not affect driver's operation. 

The downside of this bit holder is it likely won't work with most other model - it is made specifically  for this Ryobi impact driver model. 

I got inspired by Petrepa's idea ( I think he has same driver.. ) and tries to make one that does not use glue.

Recommend to use PETG to print for it's flexibility, as you need to expand the holder a bit to clip into the driver.

Print this with the flat edge facing down.