These clear mixing well trays are perfect for color mixing and micro-reactions. Challenge students to make as many colors as they can from red, yellow, and blue colored water. Discover various color reactions of acids and bases using a universal indicator. Ideal for mixing up small amounts of liquids, sprouting small seeds, or storing small items. Trays measure 13 x 9 cm (5 x 3.25 inches) each. Wells are about 1.5 cm (0.6 inches) deep. The wells in the 12 well tray are about 2.3 cm (0.9 inches) wide. The wells in the 24 well tray are about 1.5 cm (0.6 inches) wide. Lids are included.