The halls of Hogwarts school must be pretty drafty, I mean, all that stone! This is where the Hogwarts bath robe comes in handy, for those witches and wizards who need to stay cozy when they're lounging in the common room but just can't let go of uniform regulations (not mentioning any names).
Use yours after a nice hot post-Quiddich shower or even as an easy cos-play outfit.

Black Dressing Gown
100% polyester bathrobe
Oversized hood and kimono sleeves.
Two pockets.
Lined with the house's main color (with matching belt)
Features the house's crest (movie version) embroidered on the chest.
One size fits most:
Standard - Generally up to 6 Foot 2" and waist up to 38" - perfect for a nice comfy fit