The Transcend 240GB JetDrive 725 SATA III JetDrive Internal SSD TS240GJDM725 is a replacement SSD with 500 MB/s read and 430 MB/s write speeds for your MacBook. This upgrade kit includes tools, instructions, and an enclosure case that is less than 0.5" thick for housing your original drive. Inside the kit are two types of screwdrivers and a step-by-step guide on how to open your MacBook and copy over the data from your original drive to the JetDrive SSD.