Turn more accurate, consistent and concentric pen barrels with this one of a kind mandrel system. The Turn Between Centers mandrel rides on two centers rather than a typical rod so more accurate turning. There is no mandrel shaft to bend so your turned barrel will eliminate an out of round blank, producing a blank that mates precisely with your pen parts. The system includes an MT headstock insert and live MT tailstock insert - each with 7 mm pins (similar to a 7 mm mandrel shaft). Mount your bushings onto the pins, mount your pen blank, then bring the tailstock forward to secure your blank between centers. Ideal for single tube pen styles. For #1 Morse Taper Lathes.