the part number 400288 is the unique identifier for the C-053 3/8 SAE model

Operating with a normal main air pressure of 20-22 psig

minimizing downtime during service calls

equalizing pressures during operation

offering a robust safety margin over lower-rated components

IO Hvac Controls TWIN Twinning Kit 321894-709 the part number 400288 isThe iO HVAC Controls TWIN Universal Twinning Kit is a field proven solution for contractors needing to synchronize multiple HVAC units under a single control point. Commonly cross referenced as the iO TWIN or TK 400, this panel enables a single thermostat to operate two separate systems, ensuring simultaneous blower and stage activation. This kit is compatible with single stage, multi stage, and heat pump equipment, supporting up to 3 heating and 2