This package includes the main hardware to start making pens. The deluxe mandrel includes the live center saver assembly, which makes tightening up your pieces on the mandrel a snap....just bring up and tighten your tail stock and everything lines up tight and in place! Standard 7mm mandrel includes 4 bushings for standard twist pens...accepts all standard 7mm bushings for other pen kits. And the universal barrel trimmer includes the most common sizes of shafts - 7mm, 8mm, 3/8", and 10mm along with a 3/4" cutter.