| Control Unit (C400) | ||||||
| Product Code 09 | ||||||
| Product Code | System Voltage | Frequency Capacity | Number of Freq | Microphone or Handset | Options | Control Unit Series |
| A | 1 | A | A | 1 | S | 4 |
| Control Unit with Brackets only | +-12 VDC | 1 Freq | One | None | Standard | C-400 |
| B | 2 | C | C | 2 | U | |
| Mastr II cables & Speaker | +-24-48 VDC | 2 Freq | Two | Std Mil Mic | Channel Guard Monitor | |
| D | 3 | F | E | 3 | ||
| Mastr Exec II cables & Speaker | +- 12 VDC Neg Gnd Only | 4 Freq | Three | Std Mil Mic & HkSw | ||
| 4 | K | F | 4 | |||
| +- 12 VDC Pos Gnd Only | 8 Freq | Four | Handset & HkSw | |||
| G | 5 | |||||
| Five | Noise Cancl Mic | |||||
| H | 6 | |||||
| Six | Noise Cancl Mic & HkSw | |||||
| J | 7 | |||||
| Seven | Duplex Handset & HkSw | |||||
| K | 8 | |||||
| Eight | External Decoder Handset | |||||