You can see what inventory/items you have in Flex Storage in the Saltbox OS app. At the bottom of the screen, select 'Reserve Flex Storage,' then select the appropriate tab based on the type of storage request you want to view: active or future.
Note: Flex Storage is only accessible during Saltbox staffed hours (9 am to 5 pm, Monday through Friday). If you're planning on storing a large amount in Flex Storage, you may want to add an additioanl suite to your membership. See your location leaders for more details.