This pen mandrel features an adjustable length mandrel shaft. Great for turning single tube kits like Sierras, Carbaras, Razors, etc. In fact it is long enough that you can make two of each of the single tube kits at one time. This mandrel comes with 5 spacer bushings and is the normal "A" shaft size. Use a crescent wrench to tighten and loosen the collar to adjust the shaft length. For lathes with a number 2 Morse Taper headstock.