The Rid a Rat unit was developed in the desert southwest where pack rats are a major problem. It was designed by a retired aerospace engineer.
The unit is designed to make nesting uncomfortable for a pack rat thereby discouraging their nesting in protected areas such as your car engine.
It works on the principle that the light causes repeated contraction of the iris and therefore causes eye fatigue. This interferes with the ordinary behavior and causes rats and other small animals to seek other shelter for nesting, which is the primary reason vehicles are targeted as safe shelter for rat pups/young.
We have run a series of tests to determine the effectiveness of this device and have found that the area of effectiveness is up to 6 feet, just about right to protect the engine compartment of most vehicles.
The RC-2 is powered by the 12 volt battery of the vehicle and has a very low current draw. Theoretically, the vehicle battery will last over 20 years. This theoretical life exceeds the shelf life or storage life of the battery. The current draw is considerably less than even the "phantom" or self discharge rate of the battery Therefore, there are no worries about running the car battery down, even if parked for extended periods.
The RC-2B is a magnetic mount unit, the same as the RC-2 except it is powered by a separate battery pack. This is designed to be used in vehicles where the 12 volt battery cannot be easily reached.
The RC-4 is a completely self contained unit with two magnets for attachment on any metallic surface. This unit runs on two AA sized batteries that last at least 6 months. It is meant for automotive use, BBQ grills, ATVs or any other small enclosed areas.