One size doesn't fit every head!
344626
Not everyone has the same size head or the same amount of hair. The quality of the hat seems to be good but the fit is a little snug and I would have preferred it a little more roomy.
2462692
I absolutely love this hat, in theory!  I am 5'2'', and experience has told me that my head circumference is relatively normal for my size. This well-crafted, amazing, over-priced shiney Jayne hat is- sadly! - simply way too big... And not in the adjustable way ='(  am considering threading the bottom few knitted layers with tighter elastic string from my daughters craft box...? Anywho, the tag inside boasts 'Firefly', 'one size fits all'... but if you have a small head and small stature (like me!), I'm sure there are plenty browncoats out there who can point  you in the right direction for size and quality...
3332943
I'm sure this is a fine swim cap for someone with an average size head. My head is larger than average (woman) and it is simply too tight and extremely difficult to get on. When I do manage to wrestle it on, I get an instantaneous headache.

Apparently, the expectation is that one size will fit from child to adult. The bag my cap came in says 'Silicone Swim Cap for....Boys and Girls (pink).'

The barcode is X000I39TG1

Mine is heading to Goodwill with the hope that someone else will find it useful.
2855769
One size fits one not all. It's tiny. The hat says size large/xl but it must be kids sizes because it fits my head like a s/m. Requesting to return since no use for a hat that doesn't fit
3750372
This hat is for a child... or Adult with irregularly small head.  This is not a one size fits all product and a waste of my $8.
2450806
They really didn't fit any of the girls heads "One size fits most". Other then that great hats, it'll just take some creativinty to keep them on during the performance.
2099762
I have a bit of a smaller head but it works!
936683
This hat not one size fits all.  It really medium size hat that is tight on my head.  I'm hoping the hat will stretch a little to make it more comfortable.  Other than that, the is a good quality hat.
2131640
I purposefully bought this hat as others said it runs big, and my bigger nugget can never find a sun hat as they are all One size fits most. The hat is great, but is was too small for my head. I ended up cutting the inner band in a few places, allowing it to stratch out a bit, so I will keep it. I have no other choice as I have not been able to find sun hats that come in different sizes. Hat companies take note, people are different, and everyone needs sun protection!
4119752
Great hat, but is one size fits all, not adjustable. Fits up through a size L, only.
2759883
There's no size guide to how this fits. I bought this for my 7 year old nephew and it is huge! I don't know how this would even fit an adult sized head
2110758
Good quality, but unfortunately it fits a little small, so it doesn't have a slouchy fit on my head.
3912307
Great design, but I had to return the hat because it was too small.  One size fits all is not true. . .
3480414
The size of these as described in the information section sounds reasonable. I understood that there would be some leeway, and that they would fit most, if not all, heads. Unfortunately, they do not. These are tight - very tight - so tight I had trouble getting them off. How big is my head, then? Not big at all. While I'm not a pinhead, I do have a narrow, oval female head, not wide at all. I would feel fine buying these for a toddler. They fit like swimming goggles on adults.
2684858
The one-size fits all is not a good look for this type of hat - the color and design is good but just too small - too bad for me!
3806300
I love this cap but I have a large head and it didn't fit. I had to use my sewing skills to alter it to fit. I have this problem a lot. I had to alter all the caps I ordered due to chemo and hair loss. I guess since most are made in third world countries they don't think about making them adjustable!
1975888
Seems like a nice hat for the price.  However, be wary if you have a large head. It does not fit comfortably.