The type B hose adapter is designed for connecting 1.5" pool hoses to plunger valves and other pool equipments. The hose adapter converts pools with 1.3" fittings to 1.5" fittings. These hose adapters will be needed when upgrading from a low-flow pump system (3785 l/h or smaller) to a larger pump system (5678 l/h or larger). Warning: Cancer and Reproductive Harm----www.P65Warnings.ca.gov.