Muller tc 1421 panel mount digital timer 230vac 8a muller tc 1421 this muller digital timer tc 1421 is a universal countdown timer with switching output for panel mounting it is supplied with a tensioning bracket for a 46 x 46 mm cut out the adjustable timing range is a minimum 10 second to maximum of 9 hours 59 min 59 seconds an optical and audible signal notifies the user on completion of set time the output 1x changeover is active during the timing cycle there are three buttons