Simplex offers a large selection of hydraulic pump platforms, valve styles, reservoir sizes, accessories & controls to meet your everyday needs. Simplex offers the widest selection of hand pump styles, reservoir sizes, and flow rates to meet your everyday needs. Each pump has specific features that make certain models better suited for particular jobs. Simplex offers two series of air pumps; G5 and G9. G5 – Continuous duty 1.5 hp air pumps are perfect for medium size tools and cylinders.