Heat Detector, Rate Compensation, Finish Silver/White, Surface Mounting, Depth (In.) 2 1/16 in, Height (In.) 4 1/4 in, Length (In.) 2 1/16 in, Ambient Temp. Limits (F) -40 Degrees to 150 Degrees F, Coverage (Square-Ft.) 2,500 sq ft, Standards CSFM, UL