This is a 32GB kit of DDR3 SDRAM memory designed for upgrading notebook PCs, specifically Apple iMacs. The kit includes four 8GB modules with a capacity of 1600MHz and a CL11 value. It has a lifetime warranty and is of high quality. The memory comes in SO-DIMM form factor with 204 pins. It is unbuffered/non-ECC and operates at a voltage of 1.5V.