4M KidzLabs Doorbell Making Kit Complete an electric circuit for a working doorbell with this kit. Teach friends and family about converting electricity to physical movement. With a hangable loop at the top of the unit, use the doorbell as a functional and decorative gadget in the bedroom. Assemble the kit with a cross-head screwdriver and power with 2 AA batteries (sold separately). This kit is recommended for ages 8-15 with adult supervision. 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.