The POWERTEC Dust Collection with Fittings + Reducer 2-1/2 - Inch to 1-1/2 - Inch ensures fantabulous work room air quality and shop cleanliness ! . the integrity of your craftsmanship and the health of all shop workers. This superior dust collection system is with Porter-Cable Random Orbit Sander models 7334, 7335, 7336 and 333VS. The hose two fittings on the ends : 1-3/4 - Inch O.D. / 1-Inch I.D. and 1-3/16 - Inch O.D. / 1-Inch I.D. and also includes 2-1/2 - Inch to 1-1/2 - Inch reducer to fit most palm sanders and Shop-Vac products ! .