Hard plastic storage case Standard size, interchangeable with other branded sets Consists of 54 balls of various colours and 24 links: [12] Carbon (black), 4 Holes [24] Hydrogen (white), 1 Holes [6] Oxygen (red), 2 Holes [2] Nitrogen (blue), 4 Holes [4] Nitrogen (blue), 3 Holes [2] Chlorine (green), 1 Holes [1] Sulphur (yellow), 2 Holes [1] Sulphur (yellow), 4 Holes [1] Bromine (brown), 1 Holes [1] Iodine (purple), 1 Holes [16] Medium Bonds [8] Long (Flex) Bonds