A Galilean loupe is a type of magnifying glass or optical instrument that is commonly used for low magnification inspection or observation of small objects. It consists of a simple lens system that uses a convex objective lens and a concave eyepiece lens to create an upright and virtual image of the object being observed. All our galilean loupes provide a wide field of view and superior depth of field which allows for more freedom of movement. Amtech loupes are made from high quality, antireflective, achromatic coated lens. Choose from a range of 4 diferent galilean loupes (TTL1, TTL3, TTLA1 and TTLA3) with magnification from 2.5x to 3.5x. Prescription is for carrier lens and inside the loupe for working distance correction. New Wireless LED light provides powerful and round focus white light, touchable power switch and brightness adjustment, easy one-handed operating. Total only 29.8 gram (light and battery), most comfortable user experience Three batteries provide energy for a day’s work. Headlight Weight: 10gm Brightness: 35,000 Lux Light Colour Temperature: 5800 Battery Type: Lithium Ion Weight: 20gm Recharge Time: 1.5 hr Run Time: 140 min.