An ice maker is a small appliance that fits in the freezer compartment of a refrigerator. It is fed by a small tube that runs up the back of the refrigerator to an inlet valve. When the refrigerator senses that more ice cubes need to be made, the inlet valve opens and lets water flow into a special ice cube mold. To get the ice maker running, you must hook up a special type of hose from the refrigerator connection to a water source. This kit consists of 6 feet of flexible tubing called PVC hose with a built-in compression nut at both ends. Since compression nuts come in different sizes, check the manual for the size that will be needed for your model of refrigerator.