Features 1.100% brand new and high quality 2.It is made of premium K9 glass ,crystal clear,with great Optical performance 3.It is coated with anti-reflection film on the double sides 4.It can be used for Physical Optics experiment lens 5.It has 2.5 X magnifying factor,for diy magnifying lens Specification Features: 100% brand new and high quality It is made of premium K9 glass ,crystal clear,with great Optical performance It is coated with anti-reflection film on the double sides It can be used for Physical Optics experiment lens It has 2.5 X magnifying factor,for diy magnifying lens Specification: Diameter: 30mm / 1.2in Focal length: 100mm / 3.9in Center thickness :5mm Edge thickness: 2.8mm R = 15 mm Material :K9 optical glass Double coated with anti - reflective film Magnification: 2.5 times Package list: 1 x Double Convex Lens Package List