dial regulator is zinc plated/polished,various slot option available (10mmsq,12.7mm sq,10mm round,12mm round,12.7mm round)spindl dial regulator is zinc plated/polished,various slot option available (10mmsq,12.7mm sq,10mm round,12mm round,12.7mm round)spindles can be supplied on request at extra cost. Dial regulator 60 /75