5 New Black Stackable Display Tray Inserts For Jewelry Showcases & Countertops. A new set of five 10 compartment stackable black plastic tray inserts. With these inserts you are able to keep components findings or small jewelry pieces organized and visible. Easily remove the tray from the showcase to allow customers to view your jewelry from the countertop. The compartments measure 2 1/2" x 3 1/4" (63 x 82 mm). Each insert measures approximately 14 1/8" x 7 5/8" x 1" (35.8 cm x 19.2 cm x 25 mm).