Bought two of these and so happy. I put one on my son's folding bike. Amazingly, it fits his handle post part. So, he can reach is bottle faster than me :).
Big opening zipper with single compartment and waterproof, can fit my wallet, phone, keys and mini hex-tools. More than enough.
Overall, good product with good design and materials; really wish this will be availabe again (already shared my experience with other cycling mates).