Dwyer Photohelic® pressure switch/gage combines a differential pressure gage with adjustable high and low switches. Series 3000 MR, A3000, and MP Mini-Photohelic®.

Photohelic® pressure switch/gage — combines DP gage with adjustable high/low switches. For filter monitoring and fan control.
ATEX-approved Photohelic® for hazardous locations.
Compact Mini-Photohelic® for space-constrained installations.