Perfect companion to the Rancilio Silvia espresso machine. The Rocky SD is burr coffee grinder with 50mm plate grinding burrs found in entry-level commercial grinders. Capable of grinding up to 7.7lbs per hour the Rocky SD will be sure to keep up with your needs. The Rocky SD features a metal removable fork to hold your porta filter in place. Grinds directly into your porta filter. The motor of the Rocky SD is a 166-watt direct drive motor that is extremely powerful. Spinning at 1725 RPM's. This powerful grinder is quiet during operation. Rocky SD features simple controls. Change the grind setting with a simple unlock of the lever and a quick spin of the bean hopper. It can grind coffee to a fine powder or course grind in seconds. The tinted bean hopper of the Rocky SD keeps just over 1/2 a pound of whole bean coffee fresh and ready to grind on-demand.