The Phase 90's compact size and superior construction put the MXR on the map and set the standard by which all other phasers are judged. Two years later, MXR released the Phase 45 - a fuller variant. Now you can have both iconic circuits in your pedalboard at the same time, without taking up a lot of space.
The Phase 95 combines the circuitry of the Phase 90 and Phase 45 and is only half the size of a standard MXR pedal.