The ACCU-TRAC System makes the fabrication of precision models and dies easier: The model and base are poured as one, eliminating the additional work when using pins and sleeves. You save time and material, without sacrificing precision. One universal tray size, accomodates all maxillary and mandibular sizes, including quadrants. Low base height, model fits any articulator. Economical, all components are reusable, Numerical die location, immediate recognition of dies, easy die repositioning. Contains 12 pcs Precision Die Trays and 50 pcs Articulation Keepers.