This is a 33066FL01-290R Float Glass Plane Ruled Diffraction Grating, sourced from the reputable vendor MKS/Newport. The grating, which is 12.5 x 25 x 6 mm in dimension, is a Blazed Ruled Reflective Grating, designed with a Rectangular base shape.
The grating is made of soda lime ru clear material, and it is coated with a specific coating on the front side, denoted as nwr 53-290r-2641-3-1. The grating's physical data includes a blaze wavelength of 500, 1800 grooves, a blaze angle of 26.7 degrees, and an orientation vector of (1, 0, 0). The grating's order is 1, and it is designed to be used from the Front side.
The grating is designed to operate at a wavelength of 588, and it is currently in stock, as indicated by its weblink status. For more detailed information, you can refer to the vendor's website at https://www.newport.com/p/33066FL01-290R.