NACOCO Large Dog Raincoat Adjustable - Pet Shark Water Proof Clothes Lightweight Rain Jacket Poncho Hoodies with Strip Reflective Blue (3XL, Blue Shark)

this is the one i got it's their largest size, though i still wish it were a bit larger. i can see it kinda slipping off his sides, even though there are some leg straps to prevent that. i just don't think it covers his hind-midsection as much as i'd hope, but it was the biggest one i could find. better than nothing haha