Welch Allyn 3.5V Professional Diagnostic Set 3.5V Standard Ophthalmoscope Head; • 6 apertures: small, medium and large spot, target, slit and red-free filter • Dioptre range: +40 to -25 3.5V Diagnostic Otoscope Head: • Fibre optic with HPX bulb for truer tissue colour • 2.5X magnification • Insuflation port for pneumatic otoscopy • Supplied with C Cell Battery Handle.