Andover offers one of the most extensive listings of standard "off-the-shelf" interference filters in this industry. Wavelengths range from the ultraviolet through the near infrared and include many of the primary laser, mercury, biomedical and analytical spectral lines. Standard sizes include 12.5mm Ø, 25.0mm Ø and 50.0mm Ø. Square filters are only available as custom items and will be quoted upon request. All Andover filters are mounted in black anodized metal rings which provide an added measure of protection against chipping, scratching and high humidity conditions. In addition, all filters have their part number permanently engraved on their edge and each filter is supplied with a calibrated spectral bandpass data curve at no-charge. Custom spectral data is available and will be quoted upon request.