Exceptional Flow with Consistent Water Pressure. Jabsco, a recognized marine pumps and waste systems firm, has announced the new Par-Max™ Plus Series water pressure pumps – available in 4.0, 5.0, and 6.0 GPM models and provide exceptional flow and consistent water pressure to easily handle the demand of multiple outlets at one time. The Par-Max Plus patented co-injected molded diaphragm and larger heavier duty motor brushes significantly extend pump life up to 50% longer than previous models.