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 64GB UPGRADE: Consists of a single 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.