The Pro Chucker Tube Case Feeder installs on the RCBS Pro Chucker 5 or Pro Chucker 7 progressive press, converting it to an automated case feed for both Bottleneck and Straight Wall cases and can increase output by more than 25%. The Pro Chucker Tube Case Feeder includes a medium feed tube that accommodates 80% of the Pro Chucker case fits. The additional SM/LG Feed Tubes allows the user to automatically feed cases for all Pro Chucker Shell Plate Fits – but the user must have the Tube Case Feeder to use the SM/LG Tubes. Mfg: Rcbs