This is one of the perfect uses for Resources. You can add all of your lockers to the system, and then assign them to the appropriate member.
Resources can be assigned to Membership Categories. They can also be assigned using a linked Subscription so that you can charge members for their locker each year with their Subscription. This also allows members to pick or choose if they want a locker or not.
Resources can have a Form attached to them to gather any extra information that is needed about the Resource.
If you think this feature is right for your club, click to GET STARTED