DW40DOE pressure wave switch from Bircher Smart Access, a Swiss manufacturer specializing in safety and automation systems:

Technical Specifications

• Model: DW40DOE
• Type: Pressure wave switch
• Function: Pressure opens contact (Normally Closed configuration)
• Response Pressure: 2 to 150 mbar
• Operating Voltage:
  • AC: 24–250 V
  • DC: 24–50 V
• Switching Current: 20 mA to 500 mA (ohmic load)
• Output: NC (Normally Closed)
• Mechanical Life: Up to 50 million switching cycles
• Ambient Temperature Range: 30°C to +70°C
• Dimensions: 49 × 41 × 34.5 mm
• Weight: 41 g
• Connection Type: Screw terminals with 6.3 mm latch plates
• Mounting: Clamped or snap-in housing
• Materials:
  • Housing: PBT GF30
  • Contacts: AgNi
  • Sealing: EPDM
  • Membrane: Silicone
  • Spring: Stainless steel
  • Metal parts: Nickel-plated brass