TierDrop Crystal Clear Sorters are beautiful and functional. Unlike competitive units, TierDrop Crystal Clear Sorters feature clear side, back, and divider panels which let in light, helping you quickly see which slots contain mail. Large compartments accommodate oversized envelopes and small parcels. Models available from 16 to 48 slots. Add-ons also available to increase any 4-Wide Sorter up to 12 levels high. 4-Wide Sorters are ideal for small to medium companies.