Small pill container. Should hold approximately 10 pills @ 0.38" diameter and 0.185" thickness.

10/31/2017 update

The threaded part of the cap is about 5% over-sized, so you may need to scale the individual parts up/down to achieve an acceptable fit.

Cap thread OD: 0.460"
Container body thread ID: 0.438"

I had no trouble getting the cap to screw into the body by printing as-is; however, if printing this way proves problematic, your best bet is to print the container body first, measure it, and then scale the cap accordingly.