Keene's classifiers are feature a deep well so you can process more material. Purchasing the whole set will save you money and time.
This set comes with 2, 4, 8, 12, 20, 30, 50 & 100 mesh classifiers.
Classifiers and their purpose:
2 - 4 mesh: Use when out in the field. If you're panning or sluicing, a 2 or 4 mesh is an ideal classification.
8 - 12 -20 mesh: Primarily used with concentrating equipment like the Gold Cube, Keene Concentrator or the Spiral Wheel.
20, 30, 50, 100 mesh: This range of classifiers is used when you're finish panning and getting to the small gold. The 30, 50, 100 mesh is used for finish panning or if you're using a blue bowl.