Weather Covers
These covers are designed to add a warm waterproof layer that you can wrap aroun the outside of the sling to protect baby from the weather.
Some are brand specific and work better with their designated brands i.e. Ergo and some are more generic and suit all brands and styles of carrier such as the Bundle Bean.
Some of these covers are fleece lined for added warmth and some are a light shell rain cover. All are waterproof.