Model 18341 , This Listing is for 3.5v Streak Retinoscope Set Our 3.5v Streak or Spot Retinoscope Sets feature instruments with the brightest light output in the industry, reliable handles, and convenient cases. 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. It allows easy one-hand operation for spot focus and 360° spot rotation.