Kingston Technology 4 GB (1x4 GB Module) 1333MHz DDR3 PC3-10600 204-Pin SODIMM Memory for Select Toshiba Notebooks KTT-S3B/4G 4GB Module of 1333MHz DDR3 Memory for Toshiba Notebooks PA3918U-1M4G (Toshiba); PAME4008 (Toshiba) Backed by a lifetime warranty and free technical support From the industry leader in PC memory