Challenger was Digitrax' first commercially produced system. It was manufactured from 1993 to 1998.
A CT4 analog throttle that controlled 4 addresses. These were color coded.
A DB100 command station/booster.
A decoder (either HO or N scale).
The CT4 throttle is the only throttle ever manufactured by Digitrax that could not be used on other Digitrax systems.