Lechler Mini-Whirling tank cleaning nozzles are designed to clean smaller vessels up to 3 feet in diameter. All have rotating heads that create flow movement for more effective cleaning, the company says. Nozzle models include: PVDF Mini-Whirly; a stainless steel unit for 1-inch wide openings; a stainless steel slip-on nozzle; and a heavy-duty model in either POM or PVDF material with stainless steel ball bearings.