The 47-820 Shortpass Filter is a circular filter with a diameter of 12.5 mm, a thickness of 1.5 mm, and a cutoff wavelength of 900nm. This filter is sourced from Edmund Optics, a leading vendor in the optical industry, and is available for purchase on their website. The filter is designed to block light with wavelengths longer than 900nm while transmitting light with wavelengths shorter than 900nm. This makes it ideal for applications where short wavelength light needs to be isolated or emphasized. The filter is coated on both the front and back surfaces with the EDM 47-820 coating, which enhances its performance and durability. The filter has a base shape of a thin lens, which contributes to its compact design and ease of integration into optical systems. The catalog number for this filter is 47-820, and it is currently in stock on the Edmund Optics website.