The standard drip tray on the Nespresso U is tall, so we can't put a large mug on it.
With this part, you can place a mug up to about 105mm in height.
You can place a magnet in the hole at the back of this.
Size of the magnet: 5.8*2.2 mm (magnet not included)
Design credit to cub3141@Thingiverse: https://www.thingiverse.com/thing:4441408