Review on 🎒 Joy Walker Waterproof Backpack Rain Cover (15-90L) - Upgraded Anti-Slip Straps and Triple Strengthened Layers for Hiking, Camping, and Traveling by Adam Ross

This bag fits my REI Trail 25 very well. It keeps the backpack dry and stays on most of the time. The rubber seems very durable. The missing feature is that it requires a clip/carabiner/strap to attach the bag to the backpack. As you can see from the photos, the cover fits snugly when the backpack is not on. However, when the backpack is on, the backpack straps push the lid off the edge of my (and I think most) backpacks. My solution: use the binding clip above. Not elegant, but enough for now. I would give this product five stars if I was sure it would never fall off on its own.