It’s used for smoothing wood, paint, filler, and similar surfaces before finishing or repainting. The rectangular base vibrates rapidly (“orbital sanding”) while sandpaper attached underneath does the sanding.
A few visible features:
Rectangular sanding pad for flat surfaces and corners
Dust collection box at the rear
Clamp system underneath for holding sandpaper sheets
Corded electric motor
Typical uses:
Sanding furniture
Preparing doors or trim for painting
Smoothing patched drywall or wood filler
Removing old varnish or paint lightly