The Bosch FCH-350-190 is a fixed-temperature/rate-of-rise heat detector head designed for fire alarm systems in high-heat-output environments or areas unsuitable for smoke detection. It triggers at a fixed 190°F (88°C) or via rapid temperature rise (rate-of-rise). Key features include a thermistor-based sensing element protected by a durable plastic guard, RF/transient immunity for stable operation, and two built-in 360° visible LEDs for power/alarm status indication. Compatible with 2-wire, 4-wire, and POPIT bases; operates from 0°C to 49°C (32°F to 120°F); dimensions: 10.03 cm x 10.03 cm x 3.81 cm (3.95 in x 3.95 in x 1.5 in). Material: ABS plastic. The Bosch FAA-350 is a 6-inch addressable POPIT (Point of Protection Identification Technology) mounting base for smoke and heat detector heads in fire alarm systems. It enables point identification on ZONEX buses for panels like the B8512G, supporting up to 119 devices per loop. Key features include screw terminals for secure wiring, compatibility with detector heads such as FCP-350 series photoelectric smoke and FCH-350 heat detectors (not FAH-350-190 high-temp models due to thermal limits), and adjustable addresses via DIP switches (00-119). Operates at 12/24 VDC; dimensions: 152 mm diameter x 23 mm height (6 in x 0.9 in); material: fire-resistant plastic. Installation requires compliance with NFPA 72 and local codes. New, was going to be used on an install but the location changed and the heat wasn’t needed. Base has small marking on it but otherwise brand new.