From The RadioReference Wiki
The Motorola Saber SI was a radio based on the Motorola Jedi Series of radios, but in a case resembling the Motorola ASTRO Saber. Few of the series were ever produced, and, while they were only ever produced for 800 MHz operation, some enthusiasts have swapped parts and 'hacked' them onto UHF. The Saber SI is programmed with its own release of RSS, and the radio (and software) is not supported by Motorola at all. The case appears slightly shorter than an ASTRO Saber case, and the radio does not support digital, as it is a Jedi radio.
The Saber SI has been known to have been programmed with MTSX RSS, although the results of using this RSS have varied from radio to radio. While the Saber SI was only produced in 800mhz versions, the Saber SI RSS indicates that the radio was to eventually be made available in multiple band splits ranging from VHF to 2 GHz.
Below is an image of an early-production Saber SI. Note that the case stops just below the keypad buttons, unlike on Astro Sabers.