WHAT SETS THE KM5 BURR GRINDER APART? 50 MM FLAT STEEL BURRS. Durable flat steel burrs deliver a highly precise and uniform grind and are built to last for years to come. STEPLESS GRIND SIZE ADJUSTMENT. The stepless knob allows for the finest adjustments of the burrs, providing the exact grind size you need for a range of brewing methods. The powerful, direct-drive motor runs quietly and efficiently, grinding 60 grams of coffee in less than 30 seconds. The spout is designed with an internal mechanism that reduces static for a cleaner grinding experience. The glass container includes a storage lid to keep leftover coffee fresh.