The product is BAD and FAILED. As a construction material, it is EXCELLENT (silicone), but the packaging contains sizes S-M-L without including XL, resulting in the L size being too small for the KZ earphone, the front part not covering the metallic part of the KZ earphone, and irritating the ear... to the point of bleeding!!!! The original ones from KZ are much better ERGONOMICALLY (maybe anatomically for an ear that needs small or medium) to fit better. The purchase was a FAILURE, for myself and the product was thrown in the trash (fortunately, the cost was relatively low).