The MK2 Espresso Gear Attento click tamping mat is the best yet.
This mat emits an audible click when you have used the correct amount of pressure on tamping your ground coffee into your portafilter.
The level of force required to make it click is adjustable from a range spanning 10kg to 25kg per square inch of pressure.
It is constructed using materials mainly consisting of stainless steel nylon and food safe silicone.
Removing the silicone mat reveals an allen key slot, you can adjust the amount of pressure required by using this slot.
The dimensions are 107mm in diameter and 15mm in height (including the body), so the footprint is very small and handy for those who make their coffee in a confined space.
A great little tool in your arsenal to help you in your stride for consistency, there are many tools on the market which will help you do this, we think this one deserves a look, a great barista tool and a worthwhile product to have in the happy donkey racks.