The Axminster Evolution Series Woodturning Handle has an overall length of 440mm (17.1/4"). The steel shaft has a comfortable medium/hard foam covering. The steel shaft adds mass, making the turning process much smoother. The covering is durable, comfortable and gives a positive non-slip grip while you are turning. The business end has a 12-13mm ER20 collet, which firmly grips onto a 12.7mm(1/2") diameter round bar. Originally intended for use with 12.7mm double-ended turning gouges, you can of course grip any turning tool whose bar diameter is between 12mm and 13mm. ER20 collets do not lock up like conventional collets. They are interchangeable; if you need to grip a different diameter bar, then you only need purchase a suitable size collet. The collet nut has a fine thread, producing a secure grip even when tightened by hand alone. The Axminster Evolution Series Woodturning Handle includes a C-spanner and tommy bar to release the nut if required.