The Tin Side Detector allows you to determine the tin side of float glass. The instrument can test clear float glass or glass that has other specialty coatings applied to it in most applications. When the lamp is placed on the tin side of the glass, the fluorescent lamp image glows visibly. When placed on the non-tin side, the lamp image appears normal. This new design is powered by only 3-AA batteries (included), however it runs 50% longer than competing models. This new instrument is centered around a custom designed UV source that is more rugged and efficient than previous models.