This 256 MB (1 x 256 MB module) DDR2 RAM memory module is manufactured by Corsair Memory and is compatible with a DIMM 240-pin slot. Clock speed is 667 MHz. Corsair memory is specifically designed for rock-solid performance in the most demanding of applications. Data lines are specifically designed for noise immunity; clock lines are optimized for minimum skew. Corsair has many years of experience in qualifying high-performance memory, and has developed a knowledge base and track record, which is among the best in the industry. Corsair also has strict standards for product qualification; any changes in design, bill-of-materials, and/or supplier, must be re-qualified prior to shipment to end customers. These high standards have resulted in a very robust product, with extremely few failures, returns, or compatibility problems.