This is the MGS4002, a 40 x 40 mm general purpose grade plane mirror, sourced from Knight Optical. The mirror is rectangular in shape, with a thickness of 3mm, making it a thin lens type.
The mirror is made of soda lime, a common material in optical applications due to its excellent transparency in the visible light spectrum. The mirror's coating is ion-plated silver, which provides high reflectivity across a wide range of wavelengths, from 450nm to 2000nm. This makes it suitable for use in various applications, including but not limited to, visible and infrared light systems.
The MGS4002 is currently in stock and available for immediate purchase. For more information, you can refer to the vendor's website through the provided weblink.