micro-switch technology eliminates the need for a reed switch. Mounts in your tank in a vertical position, the switch activates with just .5 gpm flow. Minimal pressure drop up to 12 gpm flow. If you use a downstream chemical injector, it should be mounted on the output side of the flow switch.
Specifications:

• Maximum Operating Pressure: 4000 PSI
• Minimum Flow Required for Activation: 0.5 GPM @ 50 PSI
• Maximum Operating Flow: 12.0 GPM
• Operating Temperature Range: 40 - 180 °F
• Electrical Lead Length: 48" - 18AWG
• Max Switching Voltage: 250 VAC
• Max Switching Current: 5 AMPS
• Resistance with Leads: 30 OHM
• Electrical Service Life: 200,000 Cycles
• Mechanical Service Life: 10,000,000 Cycles
• Inlet: 3/8" x 18 NPT-F
• Outlet: 3/8" x 18 NPT-F
• Pilot: 1/4" Hose Barb
• Dimensions: 4.1" x 1.6" x 1.0"
• Weight: 1.3 LBS
• Materials: Buna-N, Brass, Plastic, Nickel Plated Neodymium