The Fidelity Silver Bullet is quite rare, particularly outside the USA. By the time it was released in 1986 the Ron Nelson program was long in the tooth. The CXG Advanced Star Chess, released at about the same time, was a much better portable peg sensory machine.
The Silver Bullet was a continuation of the Mini Sensory and Mini Sensory II series. Fidelity typically tried to extract every last drop from the Mini Sensory format by switching to a glitzy silver and black finish and pieces.
Like its predessors the Silver Bullett accepted openings and other modules, which improved the strength and scope of the machine. Included in my collection are the Challenger Advanced Chess, Book Openings 1 and Greatest Chess Games 1 modules. They are quite sought after and possibly worthy of the description rare. The photograph bottom left shows the Silver Bullet recognising the Greatest Chess Games module by lighting the three leds on the bottom row.
Perhaps the combination of the Silver Bullet and modules together justifies its inclusion in this feature.