OWC 4GB UPGRADE: Consists of a single 4GB DDR3L 1600 PC3L-12800 CL11 1Rx8 204-pin 1.35V SODIMM Memory RAM Module Upgrade memory module compatible with HP EliteBook models 840 G1, 840 G2, 850 G1 And 850 G2. 100% COMPLIANT: JEDEC-Standard and ROHS Compliant. Warranty-Safe Upgrade. Designed and Tested to Meet or Exceed all Manufacturer OEM Specs. INCREASED PERFORMANCE: Memory Upgrades are the Most Effective and Easy Way to Boost your PC's Performance. INDUSTRY LEADING: Consumer-friendly Advanced Replacement Program and Limited Lifetime Warranty, which includes Free Tech Support by Other World Computing. EASY INSTALLATION: In Most Cases, Installing Memory is an Easy DIY project. Watch our OWC Basic Installation Video for Help.