Beware Havainas sizes are confusing. I have old havainas (I think they are the unisex?) which are considerably smaller than the ones I have purchased here, despite being the same size. Unfortunately, by the time I realized that these ones were too big for me, I had removed the tags, so I kept them. I returned the other pair I bought for my boyfriend, they were massive. I am not sure the sizes truly correlate to British sizes.
Product is great though.
Costumer service is excellent, they refunded the pair I returned.