Give a gift a day right up to the holiday with the action-packed fun of “GraviTrax Advent Calendar” and set those marbles racing! This Christmas season, open the doors to 24 days of exciting GraviTrax surprises! Each compartment reveals a fun GraviTrax gift, from height tiles to tracks, from special curves to a spinner! Comes complete with 24 gifts and an extra surprise hidden within — everything you need to build a fun little marble run to race the 3 holiday-colored marbles! Makes an excellent introduction to GraviTrax, or a fun way to add additional pieces to an existing Starter-Set for repeat, year-round play! GraviTrax construction sets are a creative, expandable track system that challenges children to use their imagination to design their own marble runs! STEM-friendly concepts build critical thinking and problem-solving skills. Totally open-ended, every GraviTrax set has a boredom-busting variety of play options for hours of fascinating fun. Master the basics, then add expansion sets to build the tricked-out track of your dreams! Includes 3 metal marbles (red, green, gold), 1 rugged base plate, 1 spinner, 1 target, 1 Color Swap, 1 Trampoline, 1 Jumper, 6 tracks (1 medium, 5 short), 8 Bernoulli tracks (3 left, 3 right, 2 straight), 25 height tiles (23 large, 2 small) 3 curves, 7 special curves, 1 3-in-1; gold decoration pictured not included. GraviTrax offers lasting durability for girls and boys ages 8 and up. It's the learning toy children (and savvy adults) return to over and over again!