random orbital sander
A random orbit sander is a hand-held power sander in which the action is a random orbit. This type of sander was first introduced in the early 1990s and quickly became very popular. Random orbit sanders combine almost the speed and aggressiveness of a belt sander, with the ability to produce a finer finish than that available from a standard, slow speed, orbital finishing sander.
Because of its unique random sanding action, the tool does not leave swirl marks, and it is not sensitive to the direction of the wood grain. This makes it work very well when sanding two pieces of wood that meet at right angles. Random-orbit sanders use sandpaper disks and many random-orbit sanders now come with dust collectors. Disks are attached using either pressure sensitive adhesives or a hook and loop system. On models equipped with a dust collection feature, a vacuum effect sucks sanding dust through holes in the paper and pad, feeding it to a bag or canister.