Automotive Upgrade has released a device that alerts drivers when their tires are getting low by immediately flashing when pressure has dropped 4 psi from the original pressure.
Air Alert is a small valve cap that replaces the standard tire valve cap and immediately flashes brightly, visible to the driver from any angle approaching the vehicle.
The device improves driver safety and fuel efficiency, the company says and is more accurate and immediate than other tire pressure warning systems for a fraction of the cost. Air Alert retails at $40 for a set of four valve caps. Wholesale prices are significantly less depending on quantity.
Video of the Air Alert in action can be seen here