DEL 240V Spa Ozonator w Amp Plug The ZO-302 is for installation into spas with water capacity up to 1,000 gallons. Designed for installation underneath the skirt of the spa, the unit plumbs into the spa's air venturi to give optimum ozone dispersion through the spa's circulation system. The ZO-302 power supply and ozone generator cartridge easily snap together to mount horizontally or vertically into the mounting clamps which are secured to a solid surface.