Safe-Store Hybrid Block/Slide File System, fully assembled incuding outer shell. Economical interlocking corrugated construction. Tabs allow stacking. When used as a 4 drawer file, holds approximately 2,000 slides. When used as an 8 drawer file holds approximately 500 tissue blocks. This product contains 5, 8-drawer block files, fully assembled including the outer shell. To use for slides, simply remove the top files.