Set of 36 chunky (6-1/4 inches long x 1-1/4 inches wide) bars look like building girders with indentations and holes. Bars slide and snap together to form imaginative structures. Promotes perceptual and fine motor development and encourages cooperative play. Made of soft, durable, washable plastic in 6 bright, appealing colors, storage bin with locking lid included. Recommended for 18 months +. *EARLY STEM: 6-1/4 inches long bars are the perfect size for small hands to tackle some big building. Ideal for exploring color and shape recognition, spatial relations, and early engineering concepts. *BARS SNAP AND SLIDE TOGETHER: Bars are shaped like real building girders with indentations on each end and two evenly-spaced holes. Bars easily snap and slide so kids can create construction masterpieces. *PROMOTES PERCEPTUAL AND FINE MOTOR DEVELOPMENT: Toddlers will feel a real sense of accomplishment as they discover how to fit the indentations into the holes or snap the bars together. Their structures will grow more complex with each added bar. *DURABLE, SAFE PLASTIC: Bars are made of soft, durable, washable plastic with rounded edges so they're super safe - even if dropped on a little toe. *STORAGE BIN INCLUDED: Handy plastic storage box with locking lid makes cleanup time quick and easy and keeps all pieces together for on-the-go building fun.