Light is one of the most important factors in grass and turf quality. The best way to quantify light for growing plants is to measure photosynthetically active radiation (PAR) light between 400 and 700 - the range that promotes photosynthesis. The daily light integral (DLI) measures the total amount of PAR within a 24-hour period. • Affordable & simple, one button operation • Meter runs for 24 hours to calculate DLI • Real-time intensity levels are shown in µmol·m-2·s-1 every 4 seconds daily • Battery included • Greenhouse and Turf models available 3405G3 LightScout DLI 100 Light Meter (Greenhouse, Set of 3) 3405G LightScout DLI 100 Light Meter (Greenhouse, 1 Unit) 3405T3 LightScout DLI 100 Light Meter (Turf, Set of 3) 3405T LightScout DLI 100 Light Meter (Turf, 1 Unit)