1、WIDE COMPATIBILITY: The earplug tips feature a standard 4.0mm wide opening and are compatible with most headphones on the market. Suitable for use with 4.0mm/0.15in‑5.7mm/0.22in wireless headphones or other wired headphones with internal holes. 2、UNIQUE DESIGN: The earbuds earplug have a built in recess that does not interfere with the Bluetooth charging compartment, making these earbuds more suitable for Bluetooth headphones than normal. 3、ERGONOMIC DESIGN: Earplug replacements are comfortable to wear without sound fluctuations due to squeezing and deformation of the ear canal. The ergonomic design is not easily fatigued by long‑term wear. 4、PERFECT REPLACEMENT: Replacement earplugs are suitable for any damaged, scratched, defective or missing earplugs, giving them a new lease of life. 5、DIFFERENT SIZES: 1 pair each of small and large sizes, 3 sizes, 1 pair of earplugs for each size. The different sizes allow you to find the best fit for your earplugs.