There are 3 types of DH formulations:
Silver ring - Silver tube : lets call it silver-silver
Silver ring - Black tube : lets call it silver-black
Black ring - Black tube : lets call it black-black
silver-silver is the original formulation of DH - produced until -2nd week of Sep-2010 code 0W02.
silver-black is 1st reformulation of DH - produced since 3rd week of Sep-2010 code 0W03.
black-black V1 is the same formulation as silver-black and produce since Nov-2010 coed 0Y03.
black-black V2 is a major reformulation of DH and produced since summer 2011 ( I dont know the exact date - maybe 09-2011).
Look at the code at the bottom of the box and use the net to extract the manufacture date.
Which one do you have ?
I'll reply to you question after you provide the missing information.