The Protectowire Company offers a complete range of spot type heat detectors designed to accommodate a wide variety of applications and installation environments. The 5600 Series Heat Detector is a durable, low profile unit which protrudes only 1.7 inch (4.3cm) from the mounting surface when mounted on a recessed junction box. All 302 Series Detectors are normally open devices and are available in either 135°F (57°C) or 194°F (90°C) ratings. Each unit is constructed with a high expansion .040 anodized aluminum sensing shell and fine silver contacts which are hermetically sealed to ensure reliable operation.