This is a wall mount for a 58.55mm tamper that you probably use for your espresso machine if it's an E61. It is adapted to the Lelit Tamper that came with my Mara X (PLA481R and the other PLA481# Models).
It is recommended to use (opt. food-safe) PETG, as it is not dissolved by water or heat and is mostly safe to use with food.
The product was designed by
RolfZuckowskiUltras