Fitness Circle® Pro Firm resistance · Steel ring with latex-free grips · Ideal for studios, fitness facilities and group exercise, serious Pilates participants Enhance your workout with this professional strength Pilates 12" ring. Ideal for strength and flexibility exercises. Tone, strengthen, and challenge your muscular endurance with this professional version of the Merrithew Circle, perfect for experienced home Pilates enthusiasts and professionals, inappropriate for beginners. This Fitness Circle® Pro offers very firm resistance. It is a sprung steel ring with latex-free grips. Ideal for studios, fitness facilities, and group exercise locations where participants are seeking an extra challenge. The 12 inch version provides a uniquely firm resistance, recommended for people up to 5 ft 4" (163 cm) tall. This lists for $80 on the Merrithew site, worth every penny as no other brand ring compares. As a Pilates instructor, I know this from decades of experience.