Tony M Aug 8, 2012:

Odd usage I agree with you this sounds odd; 'jacket sheath' per se is OK, even though slightly redundant; however, the second instance of "The JACKET is offered in various SHEATHS..." seems to me simply wrong, and I wonder if the writer just got a bit muddled; the word required seems to me soemthing like 'materials' (instead of 'sheaths') — I thought perhaps it might originally have been intended to be "The jacket is / Sheaths are offered in various materials", and then the writer got a bit confused when editing?