The Edwards conventional photoelectric smoke and heat detectors are interchangeable head and base detectors using Optica smoke sensing technology and high accuracy heat sensor that provides outstanding stability and excellent response to a wide range of fires. Like their Signature series counterparts, EC2 smoke detectors feature a photoelectric chamber using Optica sensing technology providing multi criteria response discriminating real smoke from other nuisance sources. A single tri-color LED located on the housing provides alarm, trouble and standby indications.