The GG Series from Optics and Allied Engineering Pvt. Ltd. are Color Glass Optical Filters that allow transmission at a wavelength of 400 nm - 495 nm. They have a tolerance of ± 0.2mm, parallelism of up to 1 arc minutes, and flatness of 2λ (at 632.8nm). These Yellow glass optical filters have a clear aperture of greater than 90% and scratch & dig surface quality of 80/50. They have a diameter of 3 mm - 160 mm and thickness of 1mm - 6mm. These round or rectangular filters are ideal for long-pass and bandpass filter applications.