This set of Lever Action ballpoint pen bushings (equivalent to 57A) is designed for between the center turning. To use these bushings, you will need a 60 degree center in your headstock and a live 60 degree center in your tailstock. You put your prepared tube on these bushings and attach them to both centers. This eliminates the need for a mandrel shaft and the reduced length between the head and tail of your lathe will greatly reduce any out of round problems.
Made in the USA.