LEGO Transparent Neon Reddish Orange Light-Up Eye / Brain Stalk (53500 / 54359)

LEGO Transparent Neon Reddish Orange Light-Up Eye / Brain Stalk has been used in at least 11 LEGO sets over the past 18 years, since it was first used in 2006. You can also find this part in at least 2 other colors. It has the design IDs 53500, 54359 which can usually be found molded into the bottom of the part.