Dr. Joel Kaplan Anal Exerciser Kit includes a set of 3 progressively sized, pliable and durable tapered probes. Features a oversized and angled suction cup base. Made from Thermoplastic Rubber TPR. Beginner probe 3.5 inches by 1 inch. Intermediate probe 4.5 inches by 1.25 inches. Advanced probe 5.5 inches by 1.5 inches.