Mini Fiber Optic Instrument FO illumination With Halogen Bulb Technology. Bright Light unobstructed view Insufflation portFor pneumatic testing of tympanic mobility Viewing window with 3x magnification and optimized casing surface for razor-sharp images and minimal reflection.Swivelling viewing window built into instrument. Attachment clip with integrated on/off switch. Replaceable batteries. Size AA, or optional rechargeable battery