If you device has "Ultra" at the front it's a ZS405.
If it has "Ultra+" you have either a ZS406 or ZS407 and the label at the back specifies which of the two.
| | tinySA Basic | tinySA Ultra ZS405 | tinySA Ultra+ ZS406 | tinySA Ultra+ ZS407 |
| Display size | 2.8 inch | 4 inch | See Ultra | |
| Low input frequency | 100kHz-350MHz | 100kHz-800MHz, 5.3GHz in Ultra mode, 10 GHz in harmonic mode | 100kHz-900MHz, 5.4GHz in Ultra mode, 10 GHz in harmonic mode | 100kHz-900MHz, 7.3GHz in Ultra mode, 11 GHz in harmonic mode |
| High input range | 240MHz - 960MHz | - | See Ultra | |
| Resolution filters in 1,3,10 steps | from 3kHz to 600kHz | from 200Hz to 850kHz | See Ultra | |
| Max low output frequency | 350MHz | Sine wave up to 800MHz, Square wave up to 4.4GHz | Sine wave up to 900MHz, Square wave up to 4.4GHz | Sine wave up to 900MHz, Square wave up to 6GHz |
| Low output level | -76dBm to -7dBm | -115dBm to -19dBm | See Ultra | |
| High output frequency range | 240MHz - 960MHz | - | See Ultra | |
| High output level | -32dBm to 16dBm | - | See Ultra | |
| Ultra mode | - | Level calibrated up to 6GHz | See Ultra | Level calibrated up to 7.3GHz |
| Internal LNA gain | - | 20dB from 100 kHz to 4GHz | See Ultra | 20 dB from 1 MHz to 7.3 GHz, 15 dB up to 9 GHz |
| Internal step attenuator | Normal: 0-31dB, High: NA | 0-31dB | See Ultra | |
| Displayed points per scan | max 290 | max 450 | See Ultra | |
| 0-350MHz scan time | 405ms | 165ms | See Ultra | |
| Minimum zero span scan time | 1.6ms for 290 points | 14 ms for 450 points | See Ultra | |
| DANL low input at 100MHz | -146dBm/Hz | -153dBm/Hz (LNA Off) / -169dBm/Hz (LNA On) | See Ultra |
| DANL high input at 880MHz | -163dBm/Hz | - | See Ultra | |
| DANL degrading in ultra mode | - | 10dB above 2.5GHz, 25dB above 5.3GHz | 10dB above 2.5GHz, 25dB above 5.4GHz | 10dB above 2.5GHz, 20dB above 7.3GHz |
| Phase noise at 30MHz and 10kHz offset | -83dBc/Hz | -92dBc/Hz | See Ultra | -100dBc/Hz |
| Phase noise at 30MHz and 100kHz offset | -98dBc/Hz | -108dBc/Hz | See Ultra | -103dBc/Hz |
| Low input 1dB compression level | -0.5dBm | +0.5dBm (LNA Off) / -26.5dBm (LNA On) | See Ultra | |
| IIP3 without LNA | +24dBm | +18dBm (at least 2MHz apart) / 0dBm (500Hz apart) | See Ultra | |
| IIP3 with LNA | - | -8dBm (at least 2MHz apart) | See Ultra | |
| Audio out | - | 3.5mm stereo headphone plug | See Ultra | |
| FW update mode activation | Via DFU menu | Push jog button before switch on | See Ultra | |
| AM modulation depth | Fixed 30% | 10% to 100% | See Ultra | |
| FM deviation | 4kHz or 75kHz | 1kHz to 300kHz | See Ultra | |
| Modulation frequency | 50Hz to 5kHz | 50Hz to 3.5kHz | See Ultra | |
| Storage | - | Internal micro SD card slot for storing measurements up to 32GBytes | See Ultra | |
