Acoustune AEX 50 is a new type of ear gel made from SMP iFit®, a Japanese shaped memory polymer introduced by SMP Technologies back in 2008 as Shape Memory Polymer (SMP), a transparent, flexible polymer that fits snugly in the ear canal. AEX50 has a double-winged design that increases the contact area between the ear canal entrance and the skin compared to standard ear gels. The fact that the material retains its shape when worn means that it fits more snugly in the ear canal even without deep insertion. In addition to increased comfort, the increased space in the ear canal also provides a different sound field than other earpieces.The new packaging design and the separate earplug storage box make it easy to store and organize the different sizes of earplugs. New ear gels made of SMP iFit® memory polymer with transparent and flexible features Double-winged design with wide wings to increase the contact area between the ear canal entrance and the skin Increased comfort and a different soundstage performance than other earpieces The inner earplug storage box is convenient for users to store and organize different sizes of earplug products. Size: XS, S, M, L, XL (2 Pairs / Same Size per Pack) Dimension: Earbud tube diameter 3.70 mm, ear tube length 8.0 mm, short side umbrella length approx. 8.75 mm for earphone tube diameter 4 - 5.5 mm AEX50 XS: Sound hole about 9.00 mm, maximum diameter of outer umbrella about 13.55 mm, length of long side umbrella about 9.75 mm AEX50 S: Sound hole about 10.00 mm, maximum diameter of outer umbrella about 15.06 mm, length of long side umbrella about 10.25 mm AEX50 M: Sound hole about 11.00 mm, maximum diameter of outer umbrella about 16.56 mm, length of long side umbrella about 10.75 mm AEX50 L: Sound hole about 12.00 mm, maximum diameter of outer umbrella about 18.07 mm, length of long side umbrella about 11.25 mm AEX50 XL: Sound hole about 13.00 mm, maximum diameter of outer umbrella about 19.75 mm, length of long side umbrella about 11.75 mm Please refer to the attached picture