I've modeled this bit case to fit one of the regular slots inside the RolyKit box. 
The “prototype” I printed didn't have the chamfered corners and had to be cut to size.

As seen in the pictures the insert holds 12 standard precision bits, they are easy to grab and will stay in their places when the RolyKit is rolled up and carried.
It's perfect for any Star Wars cosplay repair kit!

Please note that you need to remove the devider in order to fit the bit insert to your RolyKit.
But, ofcourse, as seen in the pictures, you can then reinsert the devider after placing down the insert.

Don't forget to check out my other files and especially Star Wars props -  click here!