POWERTEC 70150   Rectangular Dust Hood for 4-Inch Hose 4-Inch opening for hose or pipe Pre-drilled mounting holes Durable, long-lasting ABS plastic material construction Best if used with hose clamp (not included) Hood measures 4-1/4-Inch x 7-Inch. 4-Inch nominal end measures 3-31/32-Inch O.D. and 3-39/64-Inch I.D.