Amplifier Unit, AC 2-wire models, NO/NC selectable, Transistor, photocoupler;Relay output SPDT, Terminal block models.Sensing head size48 mm x 48 mm x 70.5 mmTypeAmplifier UnitPower sourceAC 2-wire modelsOperation modeNO/NC selectable.Sensing head size48 mm x 48 mm x 70.5 mmTypeAmplifier UnitPower sourceAC 2-wire modelsOperation modeNO/NC selectable