Triathlon rubber duck A triathlon is a competition in which athletes do various endurance sports in a row, usually swimming, biking, and running. Triathlons come in various distances and levels of difficulty, from short, so-called sprint triathlons to long, ultra-long triathlons known as Ironman triathlons. Ironman triathlons are the longest and most demanding triathlons, which require participants to complete a swim of 3.8 km, a bike course of 180 km and a marathon run of 42.2 km. They are hosted by the World Triathlon Corporation and are named after the movie “Iron Man,” in which the main character, industrialist Tony Stark, has to overcome a major challenge. Dimensions: L: 8.5 cm W: 7.5 cm H: 7.5 cm Squeak hole: Yes Floats upright: No Material: vinyl Recommended age: For children aged 18 months and over