The standard 5 degree field of view. Greater working distance improves comfort for both practitioner and patient. Helps detect corneal abrasions with cobalt blue filter and corneal viewing lens (model 11820 only). Patented Glare Extinguishment System prevents interference from unwanted glare and reflections. Halogen HPX lamp provides bright, white light.Compatible with all existing Welch Allyn 3.5 V power sources (not included). The item "Welch Allyn Panoptic 3.5V Halogen HPX Ophthalmoscope (11820), head & eyecup only" is in sale since Saturday, June 16, 2018. This item is in the category "Business & Industrial\Healthcare, Lab & Life Science\Medical Specialties\Ophthalmology & Optometry\Ophthalmoscopes". The seller is "benevolent23" and is located in Clawson, Michigan. This item can be shipped to United States.