Duplo Pearl Light Gray Siren with Transparent Dark Blue Lights (2318 / 87072)

Duplo Pearl Light Gray Siren with Transparent Dark Blue Lights has been used in at least 6 LEGO sets over the past 20 years, since it was first used in 2004. You can also find this part in at least 3 other colors. It has the design IDs 2318, 87072 which can usually be found molded into the bottom of the part.