The Welch Allyn 3.5v Retinoscope has an external focusing sleeve that's easy to grip and easy to manipulate. Its brighter halogen light provides true tissue color and consistent, long-lasting illumination. The crossed-linear polarizing filter eliminates glare from trial lenses for easier exams. It has magnetic age-appropriate targets for dynamic retinoscopy. It allows easy one-hand operation for streak focus and 360° streak rotation. The rubber brow rest prevents scratching of eyeglasses. The interchangeable spot retinoscope can be converted to a streak retinoscope by simply changing the lamp.