Tested works perfectly before shipping.1600 MHz can be compatible with DDR 3 1333 MHz / 1066 MHz1333 MHz can be compatible with DDR 3 1066 MHzType: DDR3 Laptop;Memory Channel: Dual Channel;Function: Non-ECC;Memory Socket: SodimmFrequency:1333MHz;Number of Pins: 204pin;Capacity:4GB;Voltage:1.35V;1066MHz =CL7;1333MHz =CL9;1600MHz=CL11;Unbuffered, Non-ECC, & Non-Registeredcolor: blueMaterial: PCBDDR3 1066= PC3-8500DDR3 1333= PC3-10600DDR3 1600= PC3-12800Pins of Memory RamDDR for Desktop =184 pinsDDR for Laptop =200 pinsDDR2 for Desktop =240 pinsDDR2 for Laptop =200 pinsDDR3 for Desktop =240 pinsDDR3 for Laptop =204 pinsPlease note: this memory is just for AMD motherboard, it does not fit Intel motherboard or ECC Server .The appearance and color of different batches of products may be different, which will not affect the usePackage Contents:1 x Memory Ram2 x Cooling Vest(Random colors and appearances Do not accept designation)2 x Sticker(Random colors and appearances Do not accept designation)Only the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.