hearing aid accessories Otoscope Feature: Fiber optics transmit light system 2.5 x magnification Resuable Specula: 2.5mm and 4.0mm Insufflation Port: view tympanic membrane using an insufflator's bulb It is available with two AA alkaline or NI-MH batteries. The model of the bulb is T4954(2.5V,1.6W)