Welch Allyn 3.5v Coaxial Ophthalmoscopes are just the ophthalmoscope head. It has a halogen HPX lamp that provides 30% brighter, whiter light output for accurate tissue color and consistent long-lasting illumination. The ophthalmoscope heads have coaxial optics that produce a shadow-free spot, a larger field of view, and easy entry into undiluted pupils.