Thermostat Knob Color White Compatible Grainger Part Number 38Y156 38Y157 38Y158 38Y159 38Y170 38Y171 38Y172 Compatible Manufacturer Model Number T-4002-201 T-4002-202 T-4002-203 T-4002-204 Function External Setpoint Adjustment Includes (1) External Horizontal Mount Set Point Adjustment Dial Material Plastic Compatible Product Type T-4000 Thermostats