To ensure your wireless earbuds feel comfortable and stay put no matter what you're doing, the convenient Alternate Sizing Kit includes two pairs of ear tips and two pairs of stability bands designed to fit the unique shape of your ears. Both the ear tips and stability bands are made from soft silicone for all-day comfort and a secure fit. The ear tips rest gently but securely in your ears and spread contact evenly. The stability bands hug the contours of your ears with curved fins that grip your ears for a snug fit. And since no two ears are the same, even on the same person, swap different-sized ear tips and bands to find your best fit.