| 010 | Delete 4x kelvin triaxial cables |
| 020 | Delete Windows Controller for Parametric Analysis and Characterization |
| 0KN | Self paced training |
| 200 | 1.5m interlock, 4x coaxial, 4x kelvin triaxial cables |
| 230 | 3.0m interlock, 4x coaxial, 4x kelvin triaxial cables |
| 41501B | Pulse Generator and Expander Unit for the 4155C/4156C |
| A6J | ANSI Z540 compliant calibration with test data |
| ABA | U.S. Quick Users Guide (English localization) |
| ABJ | Japan Quick Users Guide (Japanese localization) |
| L25 | Int opt I/CV 3.0 Parallel Security Key |
| L26 | Int opt I/CV 3.0 USB Security Key |
| L27 | Not 4156C-DIV 3.0 |
| L28 | Not 4156C-DIV 3.0 (Japanese Localize) |
| L90 | Int opt 100V TEST |
| L91 | Int opt 120V TEST |
| L92 | Int opt 220V TEST |
| L93 | Int opt 240V TEST |
| PAR | Parallel Security Key |
| RMKT | Agilent Refurbished Product (Do Not Use - Certiprime Option) |
| UK6 | Commercial calibration with test results data |
| USB | USB Security Key |