Finally, an inexpensive yet very functional 3 volt otoscope for home use! Krypton Bulb with a durable lightweight all metal body and switch. A proprietary process of lens manufacturing was used for a crystal clear lens with zero distortion. Designed by a an ER physician who's goal was to design an inexpensive otoscope that would be as functional in detecting eardrum abnormalities as the $400 models used at hospitals. Each otoscope comes with a web-page link that has high resolution color photo's of normal and diseased eardrums as well as instructions written by a physician describing how to properly use your otoscope for best viewing results. It explains the important information you need to know when using an otoscope to do ear exams..