Reading the codeThe code shows the RED-S II section (SB) followed by the length. Match both from your old belt, or search by your machine’s OE part number.
Replace like for likeRED-S II SB has the same top width as B section but a thinner, low-profile body. Swapping it for a standard B belt changes how it sits in the pulleys, so replace a RED-S II belt with a RED-S II belt.
Check the idlersReverse-bend drives are hard on belts. When you fit a new belt, check idler pulleys and bearings turn freely and pulley grooves aren’t worn.