2 Cool Percussion marching machine / troop blocks ---sound effect

From 2 Cool Percussion, marching machine or also call troop blocks, this percussion instrument simulate the sound of army troops crossing a bridge or marching down the street, the sound effect as used in Santa Clara Vanguard Drum Bugle Corps 1991 show Miss Saigon. Played it on a piece of plywood or steel or plastic barrel or a timpani with the card board cover on it. Has 30 blocks made of 2“ x 2“ blocks and a 2“ x 3“ frame, built to be tough.