When adding the 4 gallon solution tank to your floor buffer, some machines like our CleanFreak® 17 inch Floor Buffer and our CleanFreak® 20 inch Floor Buffer have smaller openings which the ½” hose that comes standard will fail to fit though. This kit includes the necessary items to covert that 1/2” hose down to a 3/8” outside diameter hose, which will then fit through the apron on those machines.