The KPX010 N-BK7 Precision Plano-Convex Lens is an uncoated, 1/4 inch (6.35 mm) diameter N-BK7 plano-convex lens with an effective focal length of 6.4 mm. It has = λ/4 surface irregularity, 40-20 scratch-dig, and is designed to meet the demanding requirements of laser electro-optic applications. It is manufactured from fine annealed optical glass and polished to tight tolerances using master test plates ensures minimum wavefront distortion. Tight surface quality tolerances minimize scatter and unwanted diffraction effects. N-BK7 is an excellent material for most visible and near infrared applications. It is the most common optical glass, and it provides great performance at a good value.