Hello, thank you for your inquiry. Our Fireman's Jacket does differ between the men's and women's. The women's version is trimmer and a bit shorter than the men's. In addition, the sleeves in the men's iteration are longer and fuller.

We do hope this information is helpful.
Kind regards,
Brooks Brothers

Hello sir, we are very happy to help indeed. If you wish to wear the women's version over your BB0 Black Fleece suit, we recommend starting with a BB4 in the women's iteration. Without specific measurements, we are unable to ascertain your exact fit but have to imagine a BB4 would be best. Of course, you could always select both a BB4 and BB5 and return one within a 90 day period. Often our popular Black Fleece styles sell out quickly so this would be very wise.

If you have additional questions, feel free to contact Customer Service for prompt assistance. Simply dial 800.274.1815 and a representative will gladly answer any additional inquiries you may have.

We wish you luck with your decision.
Kind regards,
Brooks Brothers

Hello sir, thank you for your inquiry into the Black Fleece Collection Wool Fireman's Jacket. We are sorry to hear a men's BB0 did not fit properly. However, if you choose to select from the women's line, a BB3 would be best. It would essentially come down to the width of your chest- the smallest we offer in men's is 36" but for women, a BB3 is 35". This should provide the best fit for you.

We wish you luck with your selection and thank you for your patronage.

Brooks Brothers