Features a switchable onboard preamp with bass/treble controls. The Custom featured active circuitry with a switchable bright mode. The automatic transmission featured electronic control with sport and economy modes plus switchable overdrive. For this reason, many stereo receivers contained a switchable subsonic filter. Switchable projection screens can be switched between opaque and clear. Transparent mobile phones use special switchable glass technology. The 68EC000 can have either a 8-bit or 16-bit data bus, switchable at reset. The four-speed manual transmission was also available with a switchable Laycock de Normanville overdrive. Isolation of the signals of a switchable module is essential to preserve design integrity. AMD GPU equipped models before the M4800/M6800 also do not support AMD Enduro Switchable Graphics. Toyota introduced switchable shock absorbers in the 1983 Soarer. As of 2007, dynamic or switchable placements became possible. Some electronic organs have a switchable replica of this sound effect. Switchable ABS was standard on quattro versions. The detectors are switchable by the operator, depending the radiation type that is being measured.