A:Answer Hello! We're sorry to hear about your experience. You should be able to find replacement ear tips with the following part numbers: 89037-01 - Small (.5"/13mm) ear tip kit. 89037-02 - Medium (.625"/16mm) ear tip kit and 89037-03 - Large (.75"/19mm) ear tip kit. The earpiece comes with the medium size ear tip as default. If it was never changed, most likely he was using the medium one. In any case, the part numbers include their measures as well. If you have any further questions, please don't hesitate to contact our Customer Care Team at: 1-888-363-0726.