This card came with my phone along with the adaptor. I recently went on a family holiday and realised how little can actually fit in a 512MB memory card. I have had no problems in using it with any of my phones or on my PC, the speed is good. I do worry that I may lose/damage it as it is very small and fiddly when inserting into a phone. I believe buying a 512MB size is suitable only for people who have minimal requirements of musical or image files. It is most suitable for people who transfer files onto PC/Hard drive or print their photos straight away and then delete the files off the card. So in other words this size is good for frequent re-use and not storing your music collection or backing up your favourite photos. If you require a large variety of music on your mobile while out and about or wish to go on holiday a minimum of 1GB is advisable.