5D51-78 Elect Fan & Limit Control - White-Rogers: 11" Fan Limit--Fan 50F-265F--Limit 100F To 300F--Adjustable Differential--15F Minimum Fixed 25F--Fan Close On Rise Limit Open On Rise--Fan HT-- Limit HTV Electrical Rating. FEATURES: * Slotted Mounting Holes For Easy Installation. * Long Terminal Screws For Wiring - Junctions Can Be Made On Terminal Block. * Dial Has Individual Pointers For Fan Cut-In And Cut-Out Settings. * Removable Solid Copper Jumper Between Fan And lLimit Switches. * Summer Fan Switch For Ventilation Without Changing Control Settings. Has Same Fan And Limit Switch Mechanism. All Controls Should Be Installed By A Licensed Professional. FAILURE TO READ AND FOLLOW ALL INSTRUCTIONS CAREFULLY BEFORE INSTALLING OR OPERATING THIS CONTROL COULD CAUSE PERSONAL INJURY AND/OR PROPERTY DAMAGE!