module appearance

hello,
i added "List by Brand" and "List by Supplier" modules as in snapshot, , my question is how can i make these appear as the "List by Category" module:- in boxes

Hi,

You need to enter:
-cat

in the module class suffix option of the modules via the joomla modules manager.

Thank you so much, where can i find a list of possible values for this parameter and their effects ?

There is no list of parameters there.
It depends on your template.
You're using the template of our demo website, so you can use the values that we configured in the template:
-cat
-identif
-switch
-cart