Your CarTray comes pre-installed with medium size silicone pieces that fits most steering wheels.
But, you can change all four silicone pieces to small (if your steering wheel is thicker) or large size (if your steering wheel is thinner) for better fitment.
The silicone pieces have lines to depict the size.
One line = Small size (you can find these in your packaging box)
Two lines = Medium size (your CarTray comes pre-installed with these)
Three lines = Large size (you can find these in your packaging box)
You can slide out the silicone pieces to install a size that fits your steering wheel.