Tecmark TBS109A Momentary Air Switch / Pneumatic Switch.
This is a SPNO single pole normally open switch (only makes contact when the air button is pushed). normally fitted to pumps/heaters and air switch boxes fitted with PCB's
Power: 250vac 16amp resistive (i.e.. Heater) and 4amp inductive (i.e.. Pump).
Hole size required : 15mm.
Pipe Size required: 3mm.