Set permission on a folder with powershell

Set-FolderPermission.ps1

$objType =[System.Security.AccessControl.AccessControlType]::Allow
$colRights = [System.Security.AccessControl.FileSystemRights]"Modify"
$InheritanceFlag = "ContainerInherit, ObjectInherit"
$PropagationFlag = [System.Security.AccessControl.PropagationFlags]::None 
$objUser = New-Object System.Security.Principal.NTAccount("IIS_IUSRS")

$rule = New-Object System.Security.AccessControl.FileSystemAccessRule($objUser, $colRights, $InheritanceFlag, $PropagationFlag, $objType)

$objACL = Get-ACL "c:\test\Folder" 
$objACL.AddAccessRule($rule) 

Set-ACL "C:\test\Folder" $objACL