Building Set Merkur electric motors and gears:Traditional Czech metal construction kit with which you can build models by either using your imagination or by using the enclosed instructions. Everything can be easily assembled using the screws and nuts that are included in the package. It's an ideal accessory for all the larger building kits, allowing you to upgrade the models you've already built. The kit contains an electric motor, a battery control pack and a basic set of sprockets.Parameters and Specifications:Dimensions:255x180x50mmWeight:0.9kg