4M KidzLabs Combination Lock Kit This set contains a plastic lock mechanism, screw, metal shackle, sticker, and instructions. Choose your own secret code to ensure that only you can unlock your treasures. It also makes a great coin bank and secret message holder. Made of safe and high-quality materials, this Kit will last for years. This item is recommended for ages 5 and up. Challenge your child's imagination with 4M toys and kits. 4M educational toys cover a wide range of educational subjects and include science kits, arts and crafts kits, robotics kits, and more. 4M offers a wide range of toys and kits to let you build a clock, crochet a placemat, or turn your room into a planetarium--all in the name of making learning fun.