In a joint venture with SanDisk , Sony released a new Memory Stick Micro M2 format on 6 February 2006. The Memory Stick Micro M2 measures 15 × 12.5 × 1.2 mm—roughly one-quarter the size of the Duo, around the size of a fingernail—with 256 MB, 512 MB, and 1 GB capacities, with a theoretical limit of 32 GB. Maximum transfer speed is 160 Mbit/s. It comes with an adapter, much like the Duo Sticks, to ensure compatibility with current PRO devices.

The memory stick micro M2 media is approximately one-quarter the volume of ‘Memory Stick PRO Duo' media, yet only about 1.2mm thick. memory stick micro M2 media is designed as an externally removable media with a controlled eject function to prevent users losing the media. Following the trend of mobile phones which operate at 1.8 volts, the memory stick micro M2 has been designed as dual-voltage media. In addition to 1.8 volt support, the media offers 3.3 volt operation which is required for existing ‘Memory Stick PRO' compatible products.

The Sony Ericsson M600i is the first mobile phone compatible with the memory stick micro M2. This phone can store various types of content to the memory stick micro M2 media, such as contacts and email attachments as well as multimedia files including music, pictures, video clips and documents. As the memory stick micro M2 is an external storage media, it allows users to exchange this content between the mobile phone and a PC with a Memory Stick PRO slot, using the memory stick micro M2 adaptor.

Sony M2 is Compatible with : Sony Ericsson Z530i, Sony Ericsson K790i, Sony Ericsson k610i, Sony Ericsson K800i, Sony Ericsson M600i,Sony Ericsson w300i and any device with a memory stick micro slot