Similar to other products on the market that I have purchased. I like that it has the ability to easily adjust without needing to change parts. Good for an introductory to oxygen deprivation training but not as beneficial for athletes training at a more serious level. I recommend this product to beginner-level people starting their fitness journey and who want to try a new training regiment or fitness technique. Keep in mind, it is designed to challenge your breathing so plan accordingly and be safe.