Using the Osprey High-Visibility Pack Rain Cover is easy. Just unfold it and wrap it around your pack. Then, use the cinching system to secure it tightly to the main body of your pack. When choosing a size, make sure to pick the XS for 10 - 20 litre packs and the Small for 20 - 35 litre packs. As for maintenance, simply clean it with mild soap and water when it gets dirty. Avoid using harsh chemicals as they might damage the fabric. Store it in a dry place when not in use to keep it in good condition. Remember, the reflective print is for your visibility, so try to keep it clean for the best effect.