I knew what size to order because their sizing is very consistent. Would personally recommend keeping these for indoor use if you do buy them. I took the hook off and am just using it as a decoration. At all times. Its a smaller size mouse, a great travel size or if you have smaller hands its a perfect fit. Nice phone, but I wont buy your device at launch next year. But for the price, and that they fit true to size, they were a great purchase! I have been using this for for almost a year, after seeing many households in Germany with a similar product. These have been the best shoes for me while teaching not only ZUMBA, but every class I teach. On my bike, thats a trade off thats pretty easy to accept.