Good product. Easy to fit but substantial enough for the job
We bought two of these covers as we needed to protect rucksacks from water ingress in a tropical environment. It was just as well that we'd also used a plastic rucksack liner as these rain covers completely failed - in fact they made things worse!
In the case of both rucksacks we discovered that rain had got behind the covers and then collected at the base of the cover. This acted as a reservoir and wicked into the rucksacks saturating them! If it had not been for the plastic liners we'd also used then everything inside the rucksack would have been damaged.
These covers might protect from drizzle but from rain certainly not. Treat with caution and don't rely solely on them.