Synchronization Policy allows you to set preferences on how to synchronize your Amazon Items with Magento Catalog data. Create it by clicking Add Policy > Synchronization under Amazon > Configurations > Policies.
Specify a meaningful title for the Policy, then define the synchronization rule.
List RulesRevise RulesRelist RulesStop Rules
If you use Backorders or do not Manage Stock options, additional settings are required. Read more here.