1. Age: 4-6 years old
2. Develop cognitive learning ability in English/digital and learn unlocking skills,to develop children's logical thinking ability
3. Easy to switch, smooth and not hurt your hands
4. Bright colors and exquisite patterns
5. One-to-one correspondence between lock and key
6. Healthy PP material, safe and no smell, reject BPA
7. Lock size: 6.2x2.7x8 cm, key 7.3x3x0.6 cm