
As long as it's close, it shouldn't matter.
https://en.wikipedia.org/wiki/DDR2_SDRAM#Specification_standards* Some manufacturers label their DDR2 modules as PC2-4300, PC2-5400 or PC2-8600 instead of the respective names suggested by JEDEC. At least one manufacturer has reported this reflects successful testing at a higher-than-standard data rate[6] whilst others simply round up for the name.
The PC number is something like a data transfer rate. That's kinda advertising if it's only a slight delta from the standard.
In that Amazon description case, it's probably just a typo.
HTH.
Cheers,
Scott.