The MAN-25-70 is a Neutral Density Filter, specifically an Absorptive Neutral Density Filter, designed for use in the visible light spectrum (400-700nm). This filter is mounted on optical glass and features a circular shape with a 25mm diameter and a thickness of 2mm. The filter is coated with OptoSigma's proprietary Opt and-70 coating on both the front and back surfaces, ensuring high-quality performance and durability. The filter's geometry is designed in a Thin Lens shape, making it suitable for a wide range of optical applications. The catalog number for this item is MAN-25-70, and it is available for purchase from OptoSigma. According to the vendor's website, the item is currently in stock.