Check the listing for details. Underhill Underhill Drain Blaster Cleaning Nozzle. Condition: New. Listed at 93.04 USD. Underhill Drain Cleaning NozzleThe Underhill DrainBlaster uses high pressure water to propel a stainless steel nozzle through drains and clear out debris. An ideal tool for clearing 4" to 6" drain lines and catch basins. Also includes wire connection point for locating clogs or mapping out the drainage route. Features: Front jets cut through blockage; Rear jets propel nozzle through pipe and clear loosened debris; Connection: 3/4" FHT ; Minimum water pressure: 70 PSI; Heat treated stainless steel 303 for long life ; Caution: Manufacturer has pressure tested this unit up to 500 PSI. Please note the max pressure will be determined by the pressure rating of the hose you use, as the hose will burst before the nozzle. Also keep in mind, the max pressure of the piping you are sending this through as it may be less than the hose and nozzle.