Disc or indent cylinder separator separates the seeds on the basis of

A disc or indent cylinder separator separates the seeds based on Length.
Indents use a combination of pocket size, centrifugal force, friction, and gravity to make separations possible.
This instrument helps to separate seeds according to their length. The equipment consists of a slightly inclined horizontal rotating cylinder and a movable separating trough. The inside surface has small closely spaced hemispherical indentations.
Small seeds are pressed into the indents by centrifugal force and can be removed. The larger seeds flow in the centre of the cylinder and are discharged by gravity.