The Samsung 4GB PC4-21300 DDR4 2666 MHz SODIMM Laptop Memory RAM (M471A5244CB0-CTD) is a high-quality memory module designed for laptops, notebooks, and All-in-Ones. With a total capacity of 4GB and non-ECC unbuffered memory features, this RAM is ideal for enhancing the performance of your device. The single module has a frequency of 2666MHz and a bus speed of PC4-21300, ensuring efficient data transfer. Backed by a lifetime manufacturer warranty, this memory module from Samsung is a reliable choice for upgrading your computer's memory capacity. Tested.