Free replacements for rips, tears, and breaks New monofin designs to increase durability, comfort, and control Superior quality, function, and design have earned our monofins two patents (US Patents 9561401 and 9925416) Made in the USA Designed for swimming with great propulsion, control, comfort, and safety BEST PRODUCTS + BEST WARRANTY = HAPPPY MERMAIDS! The Sun Tail Mermaid monofin has been engineered and designed to move the swimmer efficiently through the water using the dolphin kick. An adjustable Velcro strap holds your feet securely in place to provide comfort, stability, and control of movement in the water. This makes performing fancy mermaid turns and flips much easier! Our foot pocket separates your feet so your ankles don’t rub together. Soft fabric cushions your feet so they don't rest on plastic like most other fins. Only our monofin comes in a rainbow of ten fun colors to match your mermaid tail! The fin's realistic ridges add beauty and give you more propulsion through the water than other fins. BEST WARRANTY- Our products are built to last. We offer the highest quality monofin for swimming GUARANTEED! Our monofins come with a 1-year warranty with free replacements for rips, tears, and breaks. Our new monofin foot pocket includes thicker neoprene, providing more comfort and durability. SIZING- Our soft foot pocket is stretchy, comfortable and fits a wide range of foot sizes. Our monofin is available in two sizes, Keiki and Nunui. The Keiki (child size) monofin fits shoe size US small child size 10 to a US women's size 7. It's made to fit children age 6 to 12. The Nunui (teen/adult size) monofin fits shoe size US women’s size 6 to size 12. The Nunui is designed to fit people ages 12 to male adult. MERMAID TAILS- You can wear your monofin all by itself or you can also match your monofin to one of our mermaid tail skins for a beautiful look. The Keiki monofin is designed to work with Sun Tails mermaid tail child sizes M, L, and XL. The Nunui monofin is designed to work with the Sun Tails mermaid tail sizes JS, JM, and JL. DIMENSIONS- The Keiki (child size) monofin is 18.5 inches (47 cm) wide and 17 inches (43cm) tall. The Nunui (teen/adult size) monofin is 24 inches (61 cm) wide and 21 (53 cm) inches tall.