... : 3.5 x 2.3 INCHFeatures:1. Optimize the battery, extend battery life upto 3 times longer or 8-10 years, eliminating ... only applicable to vehicles, but also to all appliances using lead acid battery, like UPS power supply, boat, yacht, solar lamp, tank, etc ... one piece to a new car as promotion stimulus, and sell to car drivers when they come for periodic maintenance. Lead Acid Battery Optimizer