I purchased the "Oil Yeller" which is an oil alert overflow warning device from a Canadian firm for $138.00. The system is a small self contained unit slightly bigger than a cigarette package and includes a float switch and an alarm signal. The db rating for the alarm is over
100 db by the manufacturer. Beware, the alarm can not be heard 30 feet from the device. If you need an audible overflow alert, this is not the device for you. Save your money and don't get ripped off!