Lee Auto-Drum Powder Case actuated; never spill a charge. Exclusive elastomer wiper prevents powder shearing, works great with difficult metering extruded powders. Machined body with labyrinth groove mates to the precision molded nylon drums providing a leak free fit with the finest powders. Drum is actuated by a steel sector and pinion gear train./ Same swivel adapter as our famous Pro Auto-Disk powder measure. Makes moving measure fast and convenient. Quick-change hopper has on/off valve to quickly change powders./ Sleek modern design, all gears springs and levers inside the die cast housing.