This is a Plano-Concave Lens, type of Spherical Lens, offered by Standa, a renowned vendor in the optical industry. The lens is designed with a base shape of Circular, and its geometry includes a diameter of 25.4 mm and a thickness edge of 4 mm, with the thickness at the center being slightly less at 3.9 mm. The effective focal length (EFL) of this lens is -3000 mm, indicating that it is a diverging lens, causing parallel rays to spread out.
The lens is made from n-BK7 Schott, a popular optical glass due to its excellent optical properties and relatively low cost. The wavelength for this lens is 546 nm. The lens does not come with any coating, which means it is uncoated. However, users can request coatings based on their specific requirements.
This lens is available in stock and more information can be found on Standa's website. The link to the product page is provided in the item data for convenience. This lens is suitable for various applications where a diverging lens is required.