LEGO Dark Stone Gray Connector 2 x 3 with Ball Socket and Smooth Sides and Rounded Edges (93571)

LEGO Dark Stone Gray Connector 2 x 3 with Ball Socket and Smooth Sides and Rounded Edges has been used in at least 28 LEGO sets over the past 13 years, since it was first used in 2011. You can also find this part in at least 19 other colors. It has a design ID of 93571 which can usually be found molded into the bottom of the part.