3M Magnetic Shielding with Thermosetting Rubber Adhesive Sheet 1380 is typically used for applications requiring excellent magnetic shielding properties at low frequency. Common uses include magnetic shielding at low frequency in mobile phone, personal computer, CRT, etc.3M Sheet 1380 is typically used for applications requiring excellent magnetic shielding properties at low frequency. Common uses include magnetic shielding at low frequency in mobile phone, personal computer, CRT, etc.