ProAdvantage - High Intensity Diagnostic Disposable Penlights have a high intensity, pre-focused bulb powered by two AAA batteries. The diagnostic penlights are ideal for many medical diagnostic uses, including inspection of the oral cavity, back of the throat, ear canal, or pupil responsiveness. These penlights are constructed with an aluminum contact strip to ensure a brighter light. Pocket clip is included on each penlight. These disposable penlights have a one year shelf life.