ECC REGISTERED UPGRADE: This type of memory is used in Workstations and Servers. It will NOT be compatible with standard desktop computers. Also, it cannot be mixed with UNBUFFERED -or- ECC LOAD REDUCED memory. OWC 256GB UPGRADE: Consists of 4pcs of 64GB DDR4 3200 PC4-25600 CL22 2Rx4 288-pin 1.2V ECC Registered DIMM Memory RAM Module Upgrade compatible with HP Apollo model 4200 Gen10 Plus. INDUSTRY LEADING: Consumer-friendly Advanced Replacement Program and Limited Lifetime Warranty, which includes Free Tech Support by Other World Computing. MAXIMIZE YOUR SERVER: With OWC's ECC Registered Server Memory, you will extend the life of your old infrastructure or save money when building a new one. Replacement for HP part numbers P43170-B21 P06035-B21 P06035-H21 P07650-B21 P07650-H21 P07650-K21 P25205-B21. OWC DDR4 memory is Fully compliant with JEDEC specifications, ROHS compliant, providing a warranty safe upgrade. OWC Memory is the most cost effective and simple DIY upgrade you can install to unleash your Mac or PC's full potential and speed up overall responsiveness. Become a multitasking maven when you upgrade your Mac or PC with OWC Memory. Open more apps. Open larger files. Plus, work with multiple files all at the same time. We test every OWC memory module at our in house lab so you can upgrade with the confidence that your memory is built to last. We built your OWC Memory upgrade to meet or exceed the toughest industry specs to provide years of worry-free service. OWC recommends that all DIMMs be the same capacity, speed, and manufacturer to ensure optimal memory performance.