This small slider box is 84x64mm internally and the lid has a catch to hold it closed.
It prints easily on any well set up printer at .2 layer height and I have sucessfully printed it on a calibrated ender 3 and Prusa MK3s.
There are two files one standard and one tight, if your printer is perectly calibrated print the tight one. This files works for printers like the Prusa.
For most printers print the standard version. After printing you will need to work the lid on and off several times to loosen it up a bit, this is necessary for the latch mechanism to work.
If you print the standard version and the lid doesn't fit or it's so tight you can't get it off after working it on on off to loosen it up use the scaling in the slicer to scale the lid only, across the narrow width by 1/2 a percent at a time.
This design is 100% original but, was inspired by the excellent slider box by @clocksrping https://www.myminifactory.com/object/3d-print-another-slide-top-box-93705
I just wanted a way to hold the lid in place when closed, so I designed one that would.