[Type] for a ProjectWise Folder

I am passing a ProjectWise folder into a function for processing created with:

$PWfolder = get-pwfolders -FolderID $TfolderID -JustOne 

what do I use for the Type in the Parameters in my function?

==================================================

[CmdletBinding()]
param
(
[Parameter(Mandatory=$true)]
[???]$PWFolder

)

====================================================

I tried "ProjectWiseFolder"...but that was not correct...didn't work, anyway.

maybe I didn't  specify that type correctly...or give it the right location to find that type??

"Object" works...

===================================================

[CmdletBinding()]
param
(
[Parameter(Mandatory=$true)]
[Object]$PWFolder

)

===================================================

but that seems a little Generic...

is that the only option, or is there a way to specify that this is a ProjectWise Folder.

Advice??

Thanks!

Bob