Joint Connector, Small, 2-1/2" to 3-1/4" by WoodRiver. $2.25. These concealed fittings allow work surfaces to be connected rapidly and securely. They are great for joining countertop sections together. The semi-circular fastening elements are pressed against the recess walls as tension is applied. Fits in a 35mm (1-3/8") flat bottomed hole drilled 3/4" deep. Use a router with a 1/2" straight bit to connect holes. Hole spacing on the small connector is 2-1/2" to 3-1/4".