Hynix HP 4GB PC3-14900 DDR3-1866MHz ECC Unbuffered CL13 240-Pin DIMM Single Rank Memory Module (HMT451U7AFR8C-RD 733036-581). This is a seller refurbished part in great working condition. May show signs of cosmetic wear but this should not interfere with the effectiveness of the product. Taken from a working environment.