Profile: Koenig-Pretempco., Inc. is a distributor of process control instrumentation. We also manufacture unique temperature and pressure controls. We specialize in pneumatics and electro-mechanical. Our series DPS300S differential pressure switch is virtually bulletproof. It is used in HVAC and industrial applications. Our pneumatic pressure control is the ideal choice when a pneumatic switch is needed. No power is necessary to provide either a normally open, or normally closed pneumatic signal at a predetermined set point.