Digital pressure sensors made by Turck. These are used surplus items, but still guaranteed to work.
Items are used, and may have a few marks on the housing similar to the pictured item. No major cosmetic issues.
Turck Pressure Sensor, Rotatable Housing, ¼" NPT male thread, 2 switching outputs, range (-14.5 to 145 psi) (M6832662) (6832662)