The 444pcs Molecular Model Kit Set is designed for balancing chemical equations and science learning. It is also great for creating organic structures, cyclic compounds, and biology models. This kit is perfect for students, teachers, and lab use. Made of superb plastic material, this kit is easy to install and long-lasting. It improves hands-on ability and exercises children's creativity. The kit comes with four different optional molecular model kits, allowing you to choose the one that suits your needs. Each kit includes a variety of atoms, link keys, orbitals, and a short link remover tool. Specifications: Material - Plastic, Types - 4 (Optional), Item color - Multicolor, Package size - 1: 235 * 170 * 35mm, 4: 230 * 170 * 70mm, Package weight - 1: 450g, 2: 560g, 3: 650g, 4: 850g. Package includes: 1. 122PCS Molecular Model Kit Set (59 Atoms Model + 62 Link Keys + 1 Tool), 2. 179PCS Molecular Model Kit Set (76 Atoms Model + 102 Link Keys + 1 Tool), 3. 240PCS Molecular Model Kit Set (86 Atoms Model + 153 Link Keys + 1 Tool), 4. 444PCS Molecular Model Kit Set (196 Atoms & 234 Links & 3 Orbitals & 1 Short Link Remover Tool). Key Features: Designed for balancing chemical equations and science learning Improves hands-on ability and exercises creativity Made of superb plastic material Comes with four different optional molecular model kits Includes a variety of atoms, link keys, orbitals, and a short link remover tool Material: Plastic Item color: Multicolor Package size and weight vary depending on the kit