When doing replacement or upgrading on 2016 – 2019 Buick Cascada, the bulb size guide is necessary for you to take the reference.
Jump to corresponding car model with the catalog bellow.

High Beam and Low Beam Headlight2016 – 2019 D3S
Front Fog Light2016 – 2019 H8/H11/H16
Back Up Light2016 – 2019 921
Brake2016 – 2019 1156
Front Side Marker2016 – 2019 194
Front Turn Signal2016 – 2019 7444NA
License Plate2016 – 2019 194
Parking Light2016 – 2019 7443NA
Rear Turn Signal2016 – 2019 PY21W
Map Light2016 – 2019 12961