Echo RM-520ES Manuel D'utilisation page 21

Trimming operation
Scything weeds
This is cutting by swinging the cutting attachment in a level
arc. It can quickly clear areas of field grass and weeds. Scyth-
ing should not be used to cut large, tough weeds or woody
growths.
If a sapling or shrub binds the cutting attachment, do not use
the cutting attachment as a lever to free the bind, because this
will cause cutting attachment failure.
Instead, shut off the engine and push the sapling or shrub to
free the blades.
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