Welch Allyn 11720 3.5v Coaxial Opthalmoscope Head - 18 aperature / filter combinations - 28 focusing lenses with a range of -25 to +40 diopters - Detect corneal abrasions with cobalt blue filter - Red-free filter may be used with any aperature - Polarizing filter virtually eliminates corneal reflection - Sealed optics keep out dust and dirt for years of maintence-free operation - Halogen HPX Replacement Lamp: 04900-U - LED Replacement Lamp: 04900-LED
