I have several.
https://www.aliexpress.us/item/3256806190108803.htmlThis one is really light and form fitting/aero. Great for filling with ice cubes and water and wearing when its very hot outside. Holds gels and such really close to you. Its more like an ultra running vest than most cycling marketed packs, but it works just fine.
I have another one that is a bit larger for bigger rides but i haven't been able to find it for sale in a long time. Its a slightly slimmer version of this pack, minus the front vertical pockets;
https://www.aliexpress.us/item/3256808433366823.htmlThe lower front pockets may be a little larger on mine as well, I can stick my phone in one side front and gels/snacks in the other. It has a bit of room to cram a rain jacket, or layers of clothes in during long rides and even a fold out mesh pocket thing that is big enough for a helmet to be held in. Its really comfy, so I would assume this one to be as well.
There are some USWE bags on AliExpress, but i've never tried to order one to find out how real they may be.
Sometimes Sport Pursuit has hydration packs for cheap.
