Espresso tamper with a variable design that will adjust all dimensions based on the size entered into the variable, I recommend 1 mm less than the size of your portafilter for a tight fit, but you can adjust based on your needed. STLs included are for the 2 most popular sizes, but I created this model for myself as I also like to use a tamper to refill Nespresso pods in addition to my traditional espresso machine.

The variable in questions is labeled "#width" and it will adjust the other lofts to keep a consistent flow instead of just adjusting the base. 

I printed in PETG and PLA and think the PETG model feels nicer.