These sets consist of moulded balls of different colors and sizes along with lugs of different sizes. These sets are very helpful in modeling different organic & inorganic compounds. SENIOR SET: This set consists of 150 lugs & 370 balls of prescribed colors & sizes packed in a moulded box having separate space for every particular color & size of ball JUNIOR SET: This set consists of 30 connecting lugs & 75 balls of different colors & sizes.