Redding Reloading Metering Chamber - Model 3 Universal. Used with all Redding single-chamber machines the Redding Metering Chamber converts a two-inch or four-inch case to a single-inch or four-inch grooved self-lubricating model. Just install the single- or double-stage Redding Powder Measure over the small end of the Redding Metering Chamber and lubricate using the included Teflon brush. Converts a two-inch case to a four-inch case by turning the single-ended metering spindle OVER the four-inch groove of the single-in-one metering head. Just replace the single-in-one metering head with the larger-case Redding Metering Chamber. No fine-tuning needed. The Redding Metering Chamber has been patented worldwide. For more product information on Redding Reloading Chamber please see Redding Reloading quick reference handbook (instructions included). Package Contents: Redding Reloading Metering Chamber Redding Reloading 3312: Metering Chamber - Model 3 Universal