Check the listing for details. GE 2000 Series Optical Smoke Detector Sensor DP2051. Condition: New – Open box. Listed at 8.00 USD. Condition: LIKE NEW Warranty:Prime 30 Day Warranty This is a GE 2000 Series Optical Smoke Detector Sensor. Equipped with a field-exchangeable optical block and has full certification, this optical sensor provides good looks as well as top features. This item is new and has never been used. It was originally bulk packaged and we have repackaged it for individual sale. Features: Remote test capabilities Remote signalling capabilities Optical sensor with field exchangeable optical chamber Easy numeric addressing (1-128) Enhanced communication protocol Full diagnostic self testing Polarity insensitive Full range: optical and heat Full range of I/0 units and accessories Isolator base EN54 approved VdS approved FYI - These GE 2000 Series Optical Smoke Detector Sensors are not sold in a retail box they may have some minor scuffs and scratches and we have packaged them in a bubble bag for individual sale.