A useful foam insert that allows you to carefully store lab test tubes. Holds 56 test tubes and fits shallow (F1) and deep (F2) trays only. Compartments measurements are 24mm in diameter.Allows you to carefully store lab test tubes.Holds 56 test tubes.Fits Gratnells shallow (F1) and deep (F2) trays only.Compartments measurements are 24mm in diameter.5 Year Warranty.