From Sarah Kirsten:
I originally designed this fanny pack for long cycle rides, but I quickly found it so functional and easy to wear that I started using it as my everyday bag. It stays out of the way and doesn't bounce around when you're cycling or walking. It's big enough to hold a phone, wallet, keys, sunglasses, and other odds and ends like nice rocks you pick up at the beach.
The actual lengths of zippers needed are 8 1/2" and 12 1/2" . The 9” and 14” is recommended because they are commonly available lengths, but they will have to be trimmed.