Silver King SK11 Chemical Force & Suction Pump, Double checked, All Brass Construction, dual check values - no backflow. Hose attaches to either pressure end or suction end. Pressure End: Inject chemical solutions into heating, air conditioning and solar systems without shutting system down. Open clogged drains. Open clogged fuel lines. Test radiant heat. Suction End: Draw sludge or water from fuel oil tanks. Empty toilets or traps. Drain plumbing fixtures. Bilge pump. Dozens of uses on the job, home or farm. Suction & pressure ends tapped 1/4 IPS.