This is a really easy to use handle for your Allen/Hex keys…except its a universal one-size-fits-all design. So you can just print one and use it on any of your Allen keys as you need.

Simply slide the correct size inserts onto your Allen key and clip it into the handle

It supports the following sizes:

The inserts have markings on them so you don't get them mixed up. Each notch is 1mm, and a slot cutout is 0.5mm.

Here is an annotated image of all the inserts for reference.

Also provided is a handy little tray with cutouts for the handle and all the inserts so you can keep them safe.

You can print them in the two-tone colour profile as shown in the images, or a single colour profile is also provided if you want a faster print or don't have an AMS.

And finally, if you find the inserts are two tight or too loose on your allen keys for your liking, you can print them with looser/tighter fit using the 

Check out my other useful prints:

Clip-On Drawer for DeWalt Power Tools

Screw Tray with Size Guides

Sliding Radius Gauge