Model ZS002 is a handheld thermostat substitution tool and an air conditioning system testing tool for up to two stages of heating and cooling in conventional or heat pump systems. DESCRIPTION Thermostat Screwdrivers allow removal of sensor and thermostat covers for service. DESCRIPTION Freeze Spray is for testing sensors and thermostats. Cool down the elements to test thermostat operation or point-to-point wiring verification. This non-corrosive and contaminant-free aerosol has no CFCs and saves checkout time. DESCRIPTION Model 680243-6 changeover switch is snap-acting SPDT and made to strap on to water pipes. It is used for heating / cooling changeover inputs to room thermostats. It has a fixed setpoint of 85°F and a 20°F lowside differential (off at 65°F). The maximum fluid temperature is 220°F and maximum ambient is 125°F.