The HP Model 8503A 50Ω Type-N Calibration Kit is used with “S”-parameter Test Sets such as HP Model 8503A, When using an automatic Network Analyzer such as HP Models 8507B and 8409A / B, the kit can be used with Accuracy Enhancement Programs (AIM) to remove the effects of RF errors due to directivity, port match, and frequency tracking, Option 001 should be used in applications with HP Model 8409 Network Analyzer Systems.