This is the 05D620ER.2, a 12.7 mm diameter Borofloat Economy Broadband Metallic Mirror with a thickness of 3.1mm. The mirror is protected by a silver coating, specifically ER.2, which is renowned for its broadband capabilities, covering a wavelength range of 480-20000nm.
The mirror is sourced from MKS/Newport, a trusted vendor in the optical industry. It is available for purchase directly from their website, and at the time of data collection, it was in stock. The mirror's webpage can be accessed through this link: https://www.newport.com/p/05D620ER.2.
The mirror is designed in the shape of a thin lens, making it suitable for a wide range of optical applications. Its base shape is circular, adding to its versatility. The mirror is made of borofloat33, a material known for its excellent optical properties and durability.