The Hollow Air Spinner is a unique fidget toy that serves as a useful tool for those looking to increase their lung capacity after surgery. Developed by a respiratory therapist, this air spinner is a fun alternative to traditional breathing exercises that involve blowing into a tube. Made of corn-based plastic, it is an eco-friendly option that can be used as a toy after its therapeutic benefits have been achieved. With its innovative design, the Hollow Air Spinner is a must-have for anyone looking for a fun and effective way to improve their lung function.