The SK kybix 2GB 1Rx8 PC3-12800S-11-10-B2 Mac Laptop DDR3 Memory RAM is a high-quality memory module designed for Mac laptops. With a total capacity of 8GB divided into 2GB modules, this RAM is suitable for upgrading or replacing existing memory modules in Macbook A1278 models. The DDR3 SDRAM technology ensures fast bus speed of PC3-12800 (DDR3-1600), providing efficient performance for improved speed and multitasking capabilities. Made by Elpida, a trusted brand in the industry, this memory module is a reliable choice for enhancing your computer's memory capacity.