The butterfly trainer opens 8.6 inches wide and 3.9 inches long. Made of high-quality stainless steel, it is sturdy and durable. Butterfly trainers are safe and a good choice for learning and practicing. The handle is hollowed out to reduce weight and make exercises easier. The unblade butterfly trainer is safe to practice flipping skills. The practice butterfly trainer has a tail lock to keep the trainer open or lock it securely.