Features:1) Automatically detects two or four windows2) Automatically closes windows that are not properly closed3) Operates with alarm system4) Quality guaranteedInner packing:1 set/boxDimensions: 16.5 x 12 x 4cmN.W.: 0.7 kgG.W.: 0.8kgOuter packing:50 sets/ctnDimensions: 63 x 54 x 25cmN.W.: 35kg G.W.: 40kg