LEGO Dark Stone Gray Bionicle 3 x 5 x 2 Knee Shield (53543)

LEGO Dark Stone Gray Bionicle 3 x 5 x 2 Knee Shield has been used in at least 2 LEGO sets over the past 16 years, since it was first used in 2008. You can also find this part in at least 14 other colors. It has a design ID of 53543 which can usually be found molded into the bottom of the part.