For a similar example see no. 391 in Berman, The Cleveland Museum of Art. Catalogue of Egyptian Art, and for the function and dating, see pp. 29-35 in Bianchi, "Those Ubiquitous Glass Inlays from Pharaonic Egypt," Journal of Glass Studies 25, and pp. 9-29 in "Those Ubiquitous Glass Inlays, Part II," Bulletin of the Egyptological Seminar 5.