Toyota Prius Owner's Manual page 335

Selecting tire chains
Use the correct tire chain size when mounting the tire chains. Chain
size is regulated for each tire size.
Regulations on the use of tire chains
Regulations regarding the use of tire chains vary depending on loca-
tion and type of road. Always check local regulations before installing
chains.
PRIUS_OM_OM47A19E_(EE)
2-5. Driving information
Side chain:
3.0 mm (0.12 in.)
30.0 mm (1.18 in.)
10.0 mm (0.39 in.)
Cross chain:
4.0 mm (0.16 in.)
25.0 mm (0.98 in.)
14.0 mm (0.55 in.)
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