HP P1N51AA COMP 4GB DDR4-2400MHZ 1.2V SRX8 UDIMMAddOn 4 GB DDR4 SDRAM Memory Module 4 GB (1 x 4GB) DDR4 2133 PC4 17000 DDR4 SDRAM 2133 MHz Single rank Memory CL15 1. 20 V Non ECC Unbuffered 288 pin UDIMM Lifetime Warranty VPN: P1N51AA AA SKU: RSC571011 UPC: 821455539446 UDIMM 4 GB of memory makes a perfect symmetry with your latest model processor and boosts up your computer's performance 2133 MHz of memory speed with Unbuffered signal skillfully manages the variety of apps and computational tasks