The Freeze Relief is an overflow device that allows water to escape from the sump pump discharge line if it becomes frozen or blocked for any reason. Freeze Relief is incredibly challenging to clog and works automatically, not having to be monitored. At only 6 inches tall, this low-tech solution prevents high-tech problems for your customers by increasing the life span of their sump pump by preventing backfill and even more flood damage. This device works automatically - no valves to turn and no hoses to attach. Size: 1 ½” top dia., 6” height, 4” bottom dia.