Model NOV100 - $149.97
Patent Number: 5,493,877
The Noverflow sensor is the key. The sensor is to be placed inside the overflow tub, about half way down. If a sock were to block the drain and the water begins to fill the tub it will stop when it makes contact with the sensor. Noverflow will stop the power to your washing machine and let you know with an audible alarm and a red light. Once you've taken the sock out and let the water drain, just push the button and the machine will finish its cycle.
If your washing machine doesn't use a tub, but has a drain pipe, Noverflow will still work. Just place the sensor at the opening where the discharge hose connects to the drain pipe. If the drain pipe ever gets clogged, Noverflow will stop your machine as soon as water begins to overflow.
The Noverflow sensor can also be placed under the washing machine. This will alert you to any water leaks that can be attributed to the washing machine.
Noverflow is guaranteed for one year from the date of purchase.