Edgetec Force 10 Swim Jet Nozzle for conversion to Spa use SVT nozzle (Super Venturi Technology) - this nozzle introduces venturi air from both the outside of the nozzle and centre of the nozzle producing significantly more aeration and a softer massage not possible from a dedicated swim jet. Nozzle size is 38mm/1.5". 30mm also available Flow - 526 litres per minute at 60 kpa