This is a 33025FL01-280R 12.5 x 12.5 x 6 mm Float Glass Plane Ruled Diffraction Grating, available from MKS/Newport. The grating has 1200 grooves per millimeter and is coated with a front coating of nwr 53-280r-1597-1sp.
The grating is a Blazed Ruled Reflective Grating, designed in a Rectangular base shape with a width, height, and thickness of 12.5, 12.5, and 6 millimeters respectively. The grating does not have an inner or outer radius.
The grating is made of soda lime ru clear material. It is designed to work with a wavelength of 588 nanometers. The physical data of the grating includes a blaze wavelength of 500 nanometers, a blaze angle of 17.5 degrees, and an orientation vector of (1, 0, 0). The grating is designed for the first order and the grating side is the front side.
The grating's web links are valid and the product is in stock, according to the vendor's website.