A distributor/leveler evens coffee in the basket before tamping. This reduces channeling and makes your shots more repeatable. Choose a size to match your basket (e.g., 54 mm for Breville/Sage; 58 mm for E61/Gaggia). Many home baristas use a needle (WDT) tool to break up clumps, then a distributor, then a tamper — you’ll find all three here.