The product is a 4GB Crucial DDR4 (UDIMM) 2666 MHz SDRAM Memory module. It has a total capacity of 4GB, with each module providing 4GB of memory. The memory module is non-ECC, has a DDR4 form factor, and a bus speed of PC4-21300 (DDR4-2666). It is made by Crucial, has 288 pins, and is designed for desktop computers. The module is compact, measuring 5.25 inches in length, 1.23 inches in height, and 0.03 inches in width. Made in Malaysia, this memory module is a reliable and high-performance option for upgrading your computer's memory capacity.