Specifications of SM20A1
| Dimensions | 223* 69* 53mm |
| Weight | about 230g |
| Color | black |
| PTT Key | available |
| Emergency Key | none |
| Microphone Sensitivity | -21±3 dB @ 1 kHz 3.0 V 2.2 K, 0 dB = 1 V/Pa |
| Speaker Power | 30 mW (rated); 50 mW (max.) |
| Speaker Impedance | 150 Ω±15% @ 1 kHz |
| Speaker Frequency Response | 125±4 dB @ 1 kHz at 50 mW |
| IP Rating | none |
| Operating Temperature | –30℃ to 65℃ |
| Storage Temperature | –40℃ to 85℃ |