Mounting bracket kit used to attach an opto board to the underside of many Williams/Bally pinball machines.
Brackets stand 3.5" tall, with the length from the center of the top holes to the center of the bottom holes being 2.7".
Each kit comes with 2 brackets, 4 mounting screws, 4 nuts & 4 washers.
Also great for home brew machines.
Williams/Bally reference #01-10756.