Price history on Walmart.com for
Unique Bargains Unique Bargains SN04-P 3-wire 4mm Sensor Inductive Proximity Switch PNP NO DC 10-30V 200mA New
See on WalmartProduct info
It is a component widely used in automatic control industry for detecting controlling and noncontact switching. When proximity switch is close to some target object it will send out control signal. The Proximity Sensor Switch is used for testing parts such as size and speed can also be used in frequency counters frequency pulse generator liquid level control and processing procedures for the automatic convergence. Do not apply power.
... read more.