The aerosol duo, Hydro-solv QC and Pro-Tek QT, are for hydronic cleaning and protection. This is the same technology as utilized in broadly-used liquids, but now in a convenient aerosol can. Both feature a swivel connector that allows for simple screwing onto a 3/4-inch boiler drain valve. No more looking for an adapter or the cumbersome act of turning the whole can. Both products are available in a boiler kit.