Room example, https://photos.google.com/share/AF1QipM0GkLosTlvxisP4s4DfueXpjBvBXfKWlXOO2FTlg0wTefXal7sdY9B6Fds90D8Fw?key=ZjM2b3p5alFxZWxhV0FpZTdYaFByU0tMY25Rdmp

Room example, https://photos.google.com/share/AF1QipM0GkLosTlvxisP4s4DfueXpjBvBXfKWlXOO2FTlg0wTefXal7sdY9B6Fds90D8Fw?key=ZjM2b3p5alFxZWxhV0FpZTdYaFByU0tMY25RdmpR https://photos.google.com/share/AF1QipM0GkLosTlvxisP4s4DfueX... Windows = RF-blocking conductive mesh: copper (expensive) or nickel-copper-polyester.