BJ-20D-C Knuckle-Boom Lift: Optimal Stability with Solid Chassis & Advanced Stabilization System—Stable High-Altitude Operation. 21.8m Max Working Height, 19.8m Platform Height, 230KG Load (fits 3 workers). Retracted specs: L 8.56m, W 2.38m, H 2.61m; platform size: L 1.83m, W 0.76m, H 1.1m. Wheelbase 2.65m, middle ground clearance 0.34m. 4WD2WS drive/steering, 6V8 battery; travel speed 4.8km/h (retracted)/0.8km/h (elevated). 30% gradeability, 33*12-20 tires—adapts to diverse terrains. 355 turntable rotation, 80 platform rotation, automatic leveling further enhance stability & precision. Max allowable working angle 5, overall weight 9400kg. Ideal for high-altitude maintenance, installation, large venues & industrial facility tasks.