Abstract: A tree harvester, arranged on the movable arm of a forestry vehicle includes a cutting tool having pivotable claws with releaseable locking elements for relative, mechanical locking of the claws in an inwardly pivoted position, and a longitudinally adjustable arm, interconnected between the gripping claws of the cutting elements for simultaneous pivoting of the claws outwardly and inwardly, respectively. The arm is adapted to admit, on desire, the first claw independently to be pivoted relative to the second claw, wherein the outside of the first claw includes teeth adapted for engagement with a stud, arranged in the point end of the second claw, the geometry of the claws and the length of the interconnected arm are chosen such that the point end of the first claw moves inwardly of the point end of the second claw in the simultaneous pivoting motion.