Sentra Systems, Inc.
Model 231 Multi-Sense Wet Differential Pressure Sensor
Model 231MS1
P/N: 231GMS33VD
Range: 0 to 250 PSID
Excit: 24V
Date: 1812

Appears to have been mounted, and possibly has had fluid connected, but doesn't appear to have been wired. Sold as used.