The SENSOR-1 Population Monitor is designed to monitor the population and seed flow of your planter or drill. It can monitor up to 16-rows and is available in 1-16 row configurations. The LED lights have two display modes: Mode 1 - LED lights flash each time a seed drops; Mod 2 - LED lights remain off until a row fails. the digital display can be setup to show total population, average population, seed spacing (per inch), speed (MPH) and total or single field acres. More features include a high/low population alarm and hopper-level sensors. It is a compact design measuring 8-1/2'' long, 4-1/2'' wide and only 1-3/4'' deep, and is constructed of a lightweight, durable die-cast aluminum.