Rocker box

On top of the box is a classifier sieve (usually with half-inch or quarter-inch openings) which screens-out larger pieces of rock and other material, allowing only finer sand and gravel through.

Traditionally, the baffle consisted of a flexible apron made of canvas or a similar material, which had a sag of about an inch and a half in the center, to act as a collection pocket for fine gold.

Later rockers (including most modern ones) dispensed with the flexible apron and used a pair of solid wood or metal baffle boards.

The bottom of the washing box consists of sheet metal with holes about a half an inch in diameter punched in it, or a half-inch mesh screen can be used.

The bottom of the rocker should be made of a single wide, smooth board, which will greatly facilitate cleanups.