The Timetec 8GB DDR4 2666Mhz Laptop Ram Memory is a single unit module with a total capacity of 8GB. This RAM is designed for laptops and operates at a bus speed of PC4-21300 (DDR4-2666). It is a reliable and efficient upgrade for computers that require faster and more efficient memory processing. The product does not contain any harmful materials as indicated by the California Prop 65 Warning.