Waterproof jacket for dog made by IREENUO and sold on Amazon.  (You can see it if you search on Amazon for "Dog Raincoat, 100% Waterproof Dog Warm Jacket for Fall Winter, Rainproof Coat with Adjustable & Reflective Stripes for Medium Large Dogs" -- I'm not allowed to post the exact link on Freecycle)

Red, gently used in a non-smoking home, in great shape.  Some hair stuck in the velcro (see photos). 

For sizing reference, this fit our 70 lb lab/shepherd mix who had broad shoulders and a barrel chest.  He definitely appreciated being warm and dry during walks in bad weather!