A Red-painted gearbox / output-head of a brush cutter / grass trimmer (the part that the cutting blade or trimmer head bolts onto).
• the round protective guard/deflector plate at the bottom (typical on trimmers)
• the gearbox housing with four retaining screws on its face
• the rotating output shaft in the center with a hex/flat profile for attaching the cutting head or blade, plus the retaining nut/plug above it
• a handle/upper shaft and a power cable/hose visible in the background