Abstract: A wall phone adapter is provided which accommodates a variety of removable filter modular units for interconnection between incoming telephone lines connected to a wall mounting plate and subscriber's network termination equipment. The wall phone adapter includes a cover housing for receiving snappingly a removable filter modular unit. The removable filter modular unit has an impedance blocking filter circuit mounted thereon. The wall phone adapter further includes upper and lower slidable latches so as to facilitate connections to studs formed on the wall mounting plate which has either a standard studs-spacing or a closer studs-spacing.