infaco Powercoup PW2 Assembly Instructions Manual page 19

REBOUND
When the chain at the end of the guide touches the wood, there is a REBOUND effect.
TUG
When the chain under the guide touches the wood, there is a TUGGING effect.
PUSH
When the chain over the guide touches the wood, there is a PUSHING effect
Ref.: NOT TR8 19 Index 01.