Type 44 Microphone
Series 20
| Title | Function | Dates_produced | |
|---|---|---|---|
 | 44-A | Microphone | 1933-1937 |
| 44-A (Rev. B) | Microphone | 1933-1937 | |
| 44-A (Rev. C) | Microphone | 1933-1937 | |
| 44-A (Rev. D) | Microphone | 1933-1937 | |
 | 44-B | Microphone | 1938-1939 |
| 44-B | Microphone | 1938-1939 | |
 | 44-BX | Microphone | 1940-19?? |
 | 44-BX | Microphone | 1939 |
| 44-BX (Rev. C) | Microphone | 19?? | |
 | 44-BX (Rev. D) | Microphone | ~1948 |
 | 44-BX (Rev. G) | Microphone | 1950 |
| 44-BX (Rev. H) | Microphone | 19?? | |
 | 44-BX (Rev. J) | Microphone | 1955 |
| 44-BX (Rev. K) | Microphone | 1956 | |
| 44-BX (Rev. L) | Microphone | 19?? | |
 | A440 | Microphone | 2008-2018 |
 | R44C | Microphone | 2002-2018 |
 | R44CE | Microphone | 2002-2018 |
 | R44CX | Microphone | 20??-2018 |
 | R44CXE "British Update" | Microphone | 20??-2018 |