HABA's Marble Track Musical Staircase is an acoustic extension for the marble run. This set contains 1 sound staircase, 1 bridge with bell, 1 redirection block and 6 glass marbles. Sound staircase measures 4" x 3" x 5.5". Made from solid hardwood. Compatible with all HABA building block sets (T.C. Timber not included). Recommended for 3 years and up. Made in Germany.