Polar H10 Storage box

I created this storage box, to safely store my Polar H10 heart rate sensor and strap.
The heartrate sensor and strap need to be disconnected to put the H10 in sleep mode, but as the sensor is quite small it can be easily lost.
Unfortunately Polar does not provide nor sell a storage box, so I created my own.

This box is hinged, using a piece of filament as the hinge pin.
And has special compartments to hold the sensor and strap.
To close the box, I used 2 pieces of 4x 6 mm magnets that hav