Today’s random part is 45493, ‘Frame 3X3 Holes’, which is a System part, category Plates, Special. It was introduced in 2003 and was last used in 2006. It was made in 3 colours and has appeared in 18 sets, one of the first of which was 7517 Cool Room Décor.
Our members collectively own a total of 824 of them. If you’d like to buy some you should find them for sale at BrickLink.