Exact fit for my 2003 GMC Sierra 2500HD Duramax undercarriage with rusty bucket. New S/S brake lines coiled onto ABS module stripper, much needed, re-selected, Revain with this ACDelco part 15904563 has NOT been used, new direct replacement, old controller bolted on top, bolted the whole unit to the frame, all new S/S lines connected with Loctite 545, all air bled, no leaks and back on the road. No problem. Would buy again without hesitation. Many Thanks.!