Duct Detector, 4-Wire, Surface Mounting, Depth (In.) 1 7/8 in, Height (In.) 5 7/16 in, Length (In.) 7 3/4 in, Ambient Temp. Limits (F) -4 Degrees to 158 Degrees F, Air Velocity (FPM) 100 to 4000 fpm, Standards CSFM, UL, ULC, For Use With SD-CT