PSI Woodworking Products LCDOWEL Dowel Collet Chuck System Excellent gripping for small diameter dowels and tenons Perfect to hold a pen mandrel, and other small wood projects where a tenon is used 1-Inch by 8TPI thread with 3/4-Inch by 16TPI spindle adapter, with collet closing head 5 collets: 1/4-Inch, 3/8-Inch, 1/2-Inch, 5/8-Inch and 3/4-Inch Blow-molded carrying case