Review on Waterproof Chest Sling Bag For Men And Women By Lecxci - Lightweight Outdoor Backpack by Dustin Marshall

I purchased the small size slings as gifts for a 7 and 4 year old. Lots of pockets and small size is just right for kids. I think the water bottle opening is only illustrated in one of the color options so figure on a 2" opening that will allow just a couple more inches since it is not stretchy. I found a small diameter stainless water bottle that fits easily; TAL 10 oz double wall Insulated stainless steel water bottle with wide mouth lid sold on Walmart site. The down side is it is only 10oz and it is somewhat tall. Fits into opening on sling easily but can't comment to how well pocket will retain the bottle once filled with liquid, since bottle is taller than pocket is deep. The idea here is for little ones to carry some of their own water and to that end I think opening should be just a little wider/deeper. Yes they could carry beverage in main compartment but that would take up room there for other things like a smaller turkish towel for pool or beach. These slings are super cute and functional except for that challenge.