Sony introduced the first 128 MB 3.5" MO disk in 1991 and subsequently launched 230MB 540/640MB and LIMDOW versions as well to accommodate a wide range of applications. In order to maintain the broadest application spectrum possible and ensure that older data stored on previous generations of MO are easily accessible the GIGAMO drive is designed to be able to read and write MO disks of all capacities thereby providing a secure migration path to the future. Sony's original antistatic hard coat protects the disk against scratches and dust and the shutter is made of a strong lightweight and wear-resistant aluminum alloy which contains a high magnesium content to maximize smooth disk operation.