yes yes - think I found the operation of that switch, somewhere on the internet..:
Operation: circuit 1 – terminal 2 normally closed to ground, opens at 9 - 16 psi (62.1 – 110.3 kPa); circuit 2 - terminals 1 & 3 normally open, close at 9 - 16 psi. spst, Insulated, Normally Off