Kmart 6.3L box spool holder

This is a lightweight insert for a Kmart 6.3L clip-on box to keep your filament spool firmly in place.

The box is elongated, and it creates a perfect opportunity to put in a basket for dessicant (loose or packeted) and a hygrometer.

Central axle part is replaceable (I included the source to adapt to your favourite spool). 

You will need 4 M3x8 screws (self-tap into plastic) and 16 6x3 magnets (press fit). Basket hinge is connected with a piece of filament.

The hygrometer used is a common round one from aliexpress.