The presetting device 14 must be adjusted by turning the knurled thumb {HEAD ~ screw} 16 to perform {TAIL ~ the calibration} 
to perform
The presetting device 14 must be adjusted by turning the knurled thumb { HEAD ~ screw } 16 to perform { TAIL ~ the calibration }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL