This is a great little microcache container with a spot to mount 1/4" round neodymium magnets.
Log sheets can be found here. The 1 inch or half inch seem to work okay in this container.
Print the lid and body at 100% infill for strength.
Use plyers to press fit 1/4" round magnet into the lid.
The container may be hard to open at first. Will require a few open and close cycles to free up.
Paint with your favorite spray paint to camouflage.
NOTE: Paint with lid ON so you don't affect the fit.