Multiple times scanned for virus and malware so no worry about that.
Major and minor diameters, Pitch diameters, internal and external specs, 3 wire sizes and measurements, percent thread engagement and tap drill for SAE and metric threads unc, unf, unef,unj,npt,acme and iso.
I downloaded this freeware program in 2006 and it has been awesome so far. Runing on Widows vista xp and vista 64 so far, don't know about higher versions of windows, should run on any windows version though.