OWC 4GB UPGRADE: Consists of a single 4GB DDR3L 1600 PC3L-12800 CL11 2Rx8 204-pin 1.35V SODIMM Memory RAM Module Upgrade memory module compatible with QNAP models TBS-453A, TS-1253BU, TS-1253BU-RP, TS-1253U And TS-1253U-RP. 100% COMPLIANT: JEDEC-Standard and ROHS Compliant. Warranty-Safe Upgrade. Designed and Tested to Meet or Exceed all Manufacturer OEM Specs. EASY INSTALLATION: In Most Cases, Installing Memory is an Easy DIY project. Watch our OWC Basic Installation Video for Help. INDUSTRY LEADING: Consumer-friendly Advanced Replacement Program and Limited Lifetime Warranty, which includes Free Tech Support by Other World Computing. Replacement for QNAP part numbers RAM-4GDR3L-SO-1600 and RAM-4GDR3LA0-SO-1600.