This is an original Jandy part that allows you to monitor the air, water, or solar temperature of your pool. The 15-foot cord enables you to monitor a broader range of locations; it has a 10K thermistor. This also serves as a replacement part for 7790, 7784, 7785, and Polaris S20. It is easy to use as well. This is a great way to monitor and maintain the temperature of your pool. It enables you to keep the water at a comfortable temperature, so family and friends can get full enjoyment during your next get together. This device can be used in conjunction with the AquaLink pool control system to manage the operation of your pool remotely via a cell-cell phone app and your internet router.