Watflow 1“ FQS-25 Flow Switch Liquid Water Flow Paddle Control Switch,Blue

Mounting this device in a 1 1/2" tee fitting was the cure for sensing flow in my 1" water well's output piping.There are 3 different sized brass leaves that attach to the switch armature that can also be easily trimmed to fit just about any situation.The microswitch inside the housing has a single set (SPDT) normally open & normally closed set of contacts...with a common terminal of course. The adjustment of triggering pressure is dependent on the size of the leaves and the tension that the user sets on the switch armature. It takes a couple of tries to get exactly where you need it to be, but once set up, this switch provides very consistent flow sensing/switch triggering.Used on my water well to prevent running the pump dry, this switch will pay for itself the first time it does not actuate...when flow is insufficient or non-existent.This is cheap insurance for your water pump & an easy install. Some fiddling required - but it all came out perfect in the end.This thing is well built, easy to understand and implement and simply does it's job.Highly recommended...two thumbs up!