The jacket can withstand most prolonged downpours as a result of a hydrostatic head rating of 15,000mm. Only a experience of 4 hrs in torrential rain observed some water seeping via (seams are taped), but couple jackets could withstand that. The lighter coloured back panel is recycled Italian-milled fleece-backed polyester, https://lightweight-windbreaker50405.tribunablog.com/helping-the-others-realize-the-advantages-of-closure-coat-45744360