POWERTEC 70170 5" to 4" Reducer Connect dust collection system from 5" main line to 4" branch line Connect machine with 5" port or 5" hose to 4" standard hose 4" tapered end to facilitate connection with the dust collection hose 5" end with 4-57/64" O.D. for easy installation of 5" machine port Made of durable ABS material; High-quality performance and reliability