It is well made, clear documentation and expands the use of the Water Sensor 6 to cover two areas (rather than just one with the sensor alone) and allows USB power so you don't need to replace batteries. You can leave the batteries in the Water Sensor 6 when using this dock to allow for battery backup.I'm using one dock (with one of the Water Sensor 6) to cover the pans of two water heaters. One sensor lead to each pan.