Hummel Ballet Shoes Childrens. Hummel Junior Gymnastics Slippers. The Hummel junior gym shoe is made of a soft material and has a durable, non-slip rubber sole. It has no laces; instead it has a herringbone elastic band for an easy fit while keeping your child's little feet in place. Flexible materials for a flexible and comfortable fit. Durable, non-slip rubber outsole with elastic band with chevrons.