Kingston HyperX Impact Black 8GB Kit (2x4GB) 2133MHz DDR3L CL11 SODIMM 1.35V Laptop Memory (HX321LS11IBK2/8) High-performance memory for gaming notebooks, small form factor PCs and Steam Box systems Low voltage setting at 1.35V for cooler and quieter computing Slim and sleek new look compatible with ultra-thin notebooks Easy to install - automatic overclocking; plug-and-play functionality means no adjustments in BIOS needed Reliable - 100-percent factory tested Guaranteed - lifetime warranty, free technical support