LEGO Yellow Hinge Brick 1 x 2 Vertical Locking Double (30386 / 39893)

Item may have 7 or 9 teeth. LEGO Yellow Hinge Brick 1 x 2 Vertical Locking Double has been used in at least 41 LEGO sets over the past 25 years, since it was first used in 1999. You can also find this part in at least 19 other colors. It has the design IDs 30386, 39893 which can usually be found molded into the bottom of the part.