High Quality, Soft, Real, Durable Leather. Spikes Inside! Underneath each smaller stud there are three 1/8 inch tall thumbtack like spikes. Base is adjustable with a buckle. Real metal rings.

Available in sizes;

Small: RINGS 30mm (1.2"), 35mm (1.4"), 40 mm (1.6") inner diameter.

Medium: RINGS 30mm (1.2"), 40mm (1.6"), 40 mm (1.6") inner diameter.