This heatsink has a copper base with aluminum Helicoid pins for optimal heat dissipation. The spacing and angles between the concentric rows has been precisely calculated to optimize cooling and reduce noise at air flow levels as low as 22 CFM and 23 dbA. There are two ways to install this heatsink :
Plug-and-play installation with Intel's validated retention mechanisms for OEM processors (does not necessitate removal of the motherboard for installation). Optional screw/spring assembly retention system (requires removal of the motherboard for installation).
Heatsink specifications
CNC machined, C110 copper base, 3"W x 3.3"L x .500"H, flatness better than 0.0003", micro surface finish 8 or better. 374 Helicoid Pins made of High Thermal Conductivity Aluminum Alloy, press fitted in the base. Heatsink base dimensions 3"x3.3"x1.66" Heatsink top dimension 3 3/4" x 3 1/2" Weight: 22 oz (620g)


The suggested retail price is $49.95, without a fan.
More information here