These hooks are great for my 15 month old! I took 19-21 or 20-21 as the call time that corresponds to the C4 / 5 on the shoe. My baby is 21 Barely (recently 20 starts to be limited to 21 a little big) and as crunches carve great reputation, I thought she would be too great. Especially my little has very fine foot and not the blow of feet. But they take him to the feet excellently, he runs even with no problems, although they also take these little lace slippers. I do not regret my purchase, especially since they are asymmetrically in very original. I love SpongeBob. :)