Im attempting to install a stiker c160 insert into a superior BRF 3800 series zero clearance fireplace. I need what is called a 6 inch offset adapter here is a picture of one I just purchased from chimney liner depot.com http://www.chimneylinerdepot.com/store/comersus_listCategoriesAndProducts.asp?idCategory=61 it is basically a ventinox 304. the problem is I may need a little more of an offset and/or perhaps a lower in hight offset box. Any suggestions on where to go any other manufacturers??????????? my email addresss is [email protected] any help would be great