This wind up miniature music box movement can be used where space is limited because of its small size. Even though it is small it has an amazing 18 note range. When fully wound it can play for approximately 1-1/2 minutes. The mechanism is encased in a white plastic shell that is removable if you wish the mechanism to show. This unit is wound from the bottom and the winding stem is offsset at the corner. A 7/8"L brass key is included. The dimensions with the plastic shell in place are 1-11/16"L x 1-3/8"W x 9/16"H.