The Crucial 16GB DDR3 1600MHz PC3-12800 UDIMM Desktop RAM kit includes two modules of 8GB each, providing a total capacity of 16GB. These non-ECC unbuffered modules are of Rank 2Rx8 and have a CAS latency of 11. They are designed for desktop use with a 240-pin DIMM form factor and a voltage of 1.35V. Manufactured by Crucial and backed by a lifetime warranty, these DDR3 SDRAM modules offer reliable performance for your computer system.