4M KidzLabs Diving Octopus Science Kit Study pressure and buoyancy with this Cartesian diver toy in an ordinary plastic bottle filled with water. Impress friends and family with the octopus as it dives and rises with a squeeze of the bottle. Easily slide the narrow octopus through the narrow opening of most plastic bottles. Learn and demonstrate how changes in pressure affect buoyancy in floating submerged objects. This science experiment toy 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.