This lid is made from Wisconsin Oak. The lid measures 4 1/2" x 3/4" in thickness. The lid comes as one piece of Oak and has a rabbeted lip radius of 1/2" with a 1/4" depth. This makes the large top part 1/2" in thickness and the bottom part 1/4" thickness for a total of 3/4" top to bottom thickness.
The inside dimension is 3 1/2" which is the part that fits into the jar.