Supertech X-Ray Technique Calculator Kit for use with traditional x-ray systems (film / screen) complies with JCAHO Guides. Your PB77 Kit includes: X-Ray Technique Calculator Slide Rule, Penetrometer Phantom and Master Film, Instructions, and Storage Box. This tool has been in the market since 1973. We are currently shipping Model XI. We continue to support Models IX, X, and XI. If you own a Supertech that is older than Model IX, you are working with an obsolete tool - we recommend that you replace it.