Easy to use, just don't drop them on a hard surface, DAMHIKT cause I've ruined probably 5 Dial Calipers, the Mitutoyo's I have now hold the record I've had them close to 15 years.
Try and use the knife edge near the points on turnings and get as close to the end as possible also measure the bushings in different places both on the length and also around. also don't over tighten or close too hard, Dial Calipers should be accurate to within .001 Good luck and have fun checking your bushings.