Technical Specifications:• Material: ADC12• Dimensions(Front) : 138.0mm×240.0mm×35.0mm(5.43"×9.45"×1.38")• Dimensions(rear) : 120.8mm×222.7mm×33.0mm (4.76"×8.77"×1.30")• Wall Opening Dimensions: 120.8mm×222.7mm×33.0mm• Compatible: VTO3221E-P, VTO6221E-P