... for detect the heat in house, hotel, etc 2. 4 wire heat detector mini 4-wired combined heat and smoke detectorFeature1. SMT ... Suitable for detecting the heat in house, shop,hotel, restaurant,office, building,school,bank, library and etc. Technical Specification ... red lightStandardEN54-5 Ul521 GB4716-2005Detecting rang50 square meter with the installa height of 6m-12mDimension100 mm dia * ...