The B114LPBT detector base is designed for use with System Sensor model 2151 photoelectronic and 1151 ionization detector heads. The capability of plugging these detectors into a variety of special bases makes them more versatile than equivalent direct-wired models. Refer to the System Sensor catalog for other available plug-in bases. The B114LPBT base is intended for use in 4-wire systems with terminals provided for remote annunciator and relay connections.