Now you can make the boss's Tesla open source or simply convert your mum's shopping trolley to something more to your taste for those times when you really must borrow it.

Of course when it's not called to a higher purpose it is easy to store on the fridge or a filing cabinet too.

Pockets for magnets are 10.2 diameter x 2.1 high which gives plenty of scope for holding power - I've used 10mm x 1.2 in this one and it's fine, but I'd probably double them up (or use 10x2's  if I was going to use it semi-permanently on a moving vehicle!

The attached .3mf file is set up for PETG because I like the gloss, and has a stop for magnet insaertion at 2.6mm and a colour change at 5.4mm.