Hayden Automotive fan clutches are manufactured to ensure performance and durability. Hayden offers thermal and non-thermal clutches as well as well as standard, heavy-duty and severe duty models that meet strict factory guidelines. It turns the fan 80-90 percentage of the shaft speed when engaged. It also turns the fan 20-30 percentage of the shaft speed with disengaged. It is used with deeper pitch fans. Larger working surface provides cooler running and longer life expectancy. Thicker body and deep finned faceplate dissipate more heat.