HP 621569-001 is a 4 GB memory module for notebook computers, listed by HP as a notebook memory spare part. It provides an additional memory module for a supported computer.
The module uses PC3-10600 DDR3 memory and is specified to run at 1333 MHz. These details identify the memory type and speed in HP’s service documentation.
HP describes the module as removable from the computer’s memory slot. Compatibility depends on the computer; this reference describes the part itself, not a list of supported models.