Sturdy and durable, it will not cause sound fluctuations due to ear canal squeezing and deformation. Compatible with earphones using 4.5mm to 6.5mm sound holes. Feature: 1. Material: Silicone. Scope of Application: Suitable for Earbuds Earphones with Sound Guide Holes of About 4.5-6.5mm/0.17in-0.25in.
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