Crucial MX300 275GB SSD only the 256GB are recognized

Hello all, probably this is not related to Slackware but perhaps someone has come with this problem. I just cloned my Slackware 14.2 installation to a new SSD (crucial MX300) which according to the vendor is 275GB but in the process clonezilla saw only 256GB. Has anyone come cross in a similar problem? Is this some kind of bug on clonezilla and gparted or the disk I bought is indeed 256GB?
Regards, Apostolos.