Getting a list of users and permission from a folder

I run this command to get a a list of users and permission from a folder

$project_folder = "\\servername\foldername"
get-acl $project_folder | %{ $_.Access  } | ft -property IdentityReference, AccessControlType, FileSystemRights > folder.csv.

This only lists information for 1 folder.

If i have multiple folders how should the code be modified?