A tamp through dosing ring allows you to grind directly into the portafilter, WDT, use the distributor and tamp without having grounds fly all over your counter.
Made with solid stainless steel, not aluminium. This ring is dense and would fit on 58mm baskets (tested on IMS, VST, La Marzocco baskets and generic 58mm basket). It works with 58.5 tampers and even some self levelling tampers like the normcore.
It has the ability to securely attaché itself to the portafilter with its inbuilt magnets if your portafilter supports it.