Fittr HART Sizing Kit – Important Information The Fittr HART Sizing Kit is designed exclusively for the Fittr HART Ring, matching its exact shape, thickness, and fit. To ensure proper comfort and accuracy, we strongly recommend using this sizing kit before purchasing the Fittr HART ring. The Fittr HART ring uses a unique sizing system that differs from standard ring sizes and other ring sizers. Regular size charts or third-party sizing tools will not provide an accurate fit. How It Works 1. Purchase the Fittr HART Sizing Kit 2. Wear the sample rings to find your most comfortable size 3. Use the selected size to place your Fittr HART Ring order Authenticity & Where to Buy For authenticity and correct sizing, purchase the Fittr HART Sizing Kit and Ring only from our official Brand or Brand Store by clicking the Brand Name on the product page. This ensures you receive the original products designed to work together.