This new mandrel features a 7mm mandrel shaft that slides through a headstock collet. This feature guarantees a perfectly concentric pen. The mandrel easily adapts to different length projects. Simply mount your tubes and bushings then slide the shaft to the appropriate length and lock it in place. The shorter shaft reduces the likelihood of the mandrel shaft bowing. The collet is tightened with two 7/8" wrenches (NOT included). Mandrels include 5 bushings.