Amazon.com: IKAPE 53.3mm Espresso Tamper, Premium Barista Coffee Tamper with Calibrated Spring Loaded, 100% Flat Stainless Steel Base Tamper Fits for Breville Series 54mm Portafilter Basket: Home & Kitchen
Amazon.com: 53.5mm Espresso Tamper | Fits 54mm IMS Baskets, Gaggia Classic Pro, 54mm VST Filter Baskets | Made in Italy | Walnut and INOX Steel Metal Tamper, Flat Bottom.: Home & Kitchen
Amazon.com: 53.35 mm Tamper designed to fit 54mm IMS Precision baskets. Wood handle and Food - Safe Stainless Steel base. Made in Italy: Home & Kitchen
For anyone wondering, the 53.5mm "coffee complements" tamper base on Amazon fits the Breville Infuser superbly. : r/espresso
Amazon.com: The Force Tamper Automatic Impact Coffee Tamper Adjustable Const Pressure and Autoleveling Ripp-Distribute Set New (Jelly, 53.00mm): Home & Kitchen