These DDR2 FULLY BUFFERED Modules come with Jedec/INTEL Approved Heat Spreaders and are made for the PC's. These are not the same as the Apple Approved Heat Spreaders specifically for Apple. Those are available as well but under the Apple Section. ** ALSO NOTE WHEN ORDERING THAT MOST SYSTEMS REQUIRE YOU TO INSTALL THESE IN PAIRS SO PLEASE ORDER ACCORDING TO THE SPECIFICATIONS OF YOUR SYSTEM. FEEL FREE TO CALL US WITH ANY QUESTIONS OR CONCERNS 1GB 667MHz FULLY BUFFERED DIMM $58.00 2GB 667MHz DDR2 FULLY BUFFERED DIMM $85.00 4GB DDR2 667MHz FULLY BUFFERED DIMM $500.00