The lock may look simple, but it contains lots of mysteries.
Easy to take apart and difficult to reassemble. Not only it can enhance your ability, and can even be an extraordinary plan.
Suit for both children and adult.
Use your brain, exercise your patience, is unable to untie the knot, but as long as the master of the structure, is sure to solve.
Oil paint:Eco-friendly paint
Children must use it under the adult's tutelage.
Don't keep the toy in the mouth to prevent children devour small parts in the toy.