Its study and I enjoy using it. I finally decided to look at the directions that came in the handy storage bag and what do I read but ?not for use on cars with airbags?. Capte bien les petites et hautes fréquences de voix. These boots were purchased for my 14 year old, as the style looked like what she wanted. NO disappointment. Noise cancelation is kinda. The design is awesome but I would say they run a tad small. The book demolishes a commonly held view that the post civil war imposed governments were totally inept and corrupt. I have been a big fan of the Sketchers Go Walk range but thought I would give these a try. Good size for the price, but a bit disappointed in the quality.