This is the glow-in-the-dark construction kit that lets children build the frame for any fort, castle or playhouse they can imagine using just two simple components. The plastic spans fit snugly into the sockets of spherical, phosphorescent connectors, resulting in a structure so sturdy that children can throw a bed sheet (not included) over the roof to complete a private hideaway. Each glowing connector bears 18 sockets that make possible angles in 45-degree increments, so children can build imaginative structures on the fly. Easy-to-follow plans for more advanced structures like domes or even a spaceship can be downloaded from the manufacturer's website. The lightweight components are portable to any playroom, and the spans disassemble easily to make tear-down simple and fast. Set includes 44 16"-long spans and 25 2 1/2" diameter spherical connectors that create up to a 27' cu. structure. Ages 5 and up. (4 lbs.)