HELIOS-PREISSER 0253 301 Brake disc caliper gauge. Made of special steel with satin chromed reading parts. Locking screw. Jaw length 50mm. Measures 0-50mm. Accuracy 0.1mm. Made in Germany. Ho do the Germans win the race? Careful attention to detail, and precision measurements!
(1.) The small measuring block and thumb screw at the top right is used to lock the reading.
(2.) Make sure the screw is just loose so the block can slide.
(3.)Open the arms wide and put the tips on either side of the disc, at the place you want to measure.
(4.)Slide the arms together, leaving the gap between the arm and the measuring block. The measuring block should be pulled along by the pin. But keep the gap!
(5.) Once the measuring tips touch the disk, tighten the thumb screw to lock the reading. You can then slide the arms open and easily remove them without disturbing the reading.
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