I have a 637 that lives in the door of my truck. I bought one the Mika pocket holsters to keep it clean. It's very well made and has a rubber-like fabric to keep it in your pocket if you need to deploy it in a hurry. I hardly ever carry it but it's handy in a coat or pants pocket for the rare occasion when I do.
https://mikaspocketholsters.com/product/pocket-holster/#prettyPhoto
