All Kits TANDEM kit The Tandem kit allows for two units to be joined together. Quick and easy assembly withing three minutes. Tandem Kit KAYAK kit The Kayak kit turns your inflatable board into a two person kayak. Kayak Kit PADDLE kit The Paddle kit allows you to use the inflatable board as a stand up paddle board. Paddle Kit Benefits of these Premium Water Bikes Stable Easy to Assemble Lightweight Low-impact workout for all age groups Experience underwater aquatic life while cycling Eco-friendly, powered by human energy Kits and accessories available to extend usage Made in Spain using high-quality materials Red Shark Bikes are the premium water bikes taking the fitness and leisure world by storm.