KZ 6 PCS Sound Insulation Noise Cancelling Memory Foam Earbuds Kit for All In-ear Earphone, Size: L & M & S 1. Contains three models of large, medium and small, one pair of models. 2. The advantages of memory cotton: very flexible, comfortable fit to the ear canal, not easy to slip. Soft and comfortable, it lasts longer in the ear, effectively reducing ear fatigue. 3. The thickened earmuff design effectively reduces external noise and improves the low frequency sense. 4. After assembly, the sound insulation effect of the earphone can be enhanced, and the sound signal transmission loss does not exceed 2dB, thereby improving the low frequency performance of the earphone from the physical structure. 5. Effectively solve the problems caused by ordinary silicone earmuffs, such as long-term wear, ear discomfort and so on. 6. Foam technology based on memory ear cotton, made by conforming to the shape of human ear canal, softened by body temperature heating, the shape and size of your ear canal will change due to exercise and temperature, memory cotton earmuffs will also Follow your ear canal and change and become flexible. Daily earphones such as talking, singing, running, sunbathing, etc. can accompany you. 7. Shape memory for about 5 seconds, can adapt to different types of ear canal, no sound fluctuations caused by the deformation of the ear canal. 8. Widely compatible with 90% of the mainstream earphones in the market. Parameter: 1. L-size: height 10.5mm, outer spacing 13mm, inner spacing 4.2mm. 2. M-size: height 10.4mm, outer spacing 12mm, inner spacing 4.2mm. 3. S-size: height 10.3mm, outer spacing 11mm, inner spacing 4.2mm.