System Sensor offers an 8 1/2" x 11" strobe coverage ceiling template for its SpectrAlert series. The easy-to-read transparent 1/8"-1' scale template is printed on heavy gauge polyethylene and three-hole punched. The template can be used to plan the necessary strobe candela range vs. the rectangular ceiling area and height required for effective strobe coverage. The template features the candela range of 15 to 95 cd, the ceiling are from 20' x 20' to 50' x 50' and ceiling heights 10' to 30'. Sensor.