The Keeler Practitioner Ophthalmoscope is designed with the positive maywheel lens control that allows you to select a range of lens powers from +40D to - 25D. This allows detailed examination of the ocular structures and ease of use for spectacle wearers. The Practitioner ophthalmoscope includes 6 beams for a full diagnostic capability and a blue filter, particularly useful for assessing corneal scratches in children. The Practitioner ophthalmoscope has a red free filter for enhanced vessel examination can be used with both diagnostic beams, particularly useful for diabetic assessment and monitoring. A soft integral brow rest allows for easy positioning and protects your lenses if you are a spectacle wearer. The Practitioner ophthalmoscope head and bulb are to be used with the 3.6v Keeler Practitioner ophthalmoscope handle.