E-AFM-V2: ENVIROMUX air flow sensor 

• Reliable mechanical solution for monitoring air flow
• Reacts to any condition causing insufficient flow of air such as malfunctioning cooling fan, increased friction, or physical blockage
• Ideal for direct monitoring of a cooling fan, HVAC duct, or under a raised floor
• Switch contact is open when air flow is >2.6 ft/s (0.8 m/s)