Show also usage in model: FR21B FELLING HEAD FR21B HARVESTER FR21B HARVESTER HEAD Select parts group: 44 Cutting Mechanisms 4401 Blades & Delimbing Elements 4413 Miscellaneous, shields, cutting mechanisms 4441 Main Frame 4446 Structural Rotator Joint 4463 Lines, Hoses & Fittings 4465 Cylinders 4467 Motors 4478 Sensors