The 37717 series CoolFin heat sink has been designed to offer superior cooling for the Intel Pentium "Prescott" microprocessor. It is available in different speeds or can be fitted with a thermistor controlled fan for motherboards without variable speed fan technology. These fan options help the customer match cooling requirements with acoustic goals. The 37717 series fin package has been maximized to meet thermal performance and weight requirements. In the center fin group, copper is used directly above the heat source to maximize thermal efficiency. The outer fins are made up of lighter aluminum material to save weight. The two heat pipes further increase efficiency and create 16-17% margin at the highest fan speed; this allows customers to explore lower speed fans for better acoustics. The innovative "half-moon" base design leaves tradition behind and saves weight, while achieving high performance to meet the needs of Intel's hottest new processor. The standard heat sink comes with a 70,000 hour MTFB dual ball bearing fan, and ShinEtsu G-751 thermal interface material. Custom fans and interface are available on request. * Intel and Pentium are registered trademarks of Intel Corporation