The Crucial 4GB DDR4-2666 SODIMM Laptop Memory is a high-quality RAM module designed for laptops. With a total capacity of 4GB and a form factor of SO-DIMM, this module is ideal for upgrading or replacing existing memory modules in laptops. The DDR4 SDRAM technology ensures fast data transfer speeds at a bus speed of PC4-21300 (2666 MHz). The Crucial brand is known for its reliable and compatible memory solutions, making this product a great choice for improving the performance of your laptop.