Please help me I.D. this tool...

[SDIceMan]

Hi all. This came in a mixed tool lot from the local auction and I'm not sure of it's use or value. I'm guessing a micrometer of some sort? There are no markings on it aside from the sticker from the most recent calibration. Thanks!

 

[MRBeyer]

brake rotor micrometer

I am thinking brake rotor micrometer. Not necessarily for checking thickness as much as variance and warping.