The N75T-M from Nascom is a recessed 3/8" press fit standard NdFeB neodymium, grade N35 nickel plated magnet, tan. The N75 Series standard length 3/8" recessed contact protects all nonferrous (e.g. wood, aluminum and vinyl) doors and windows in both residential and commercial settings. The N75 is the installer's choice of contact configuration where drill depth is not a concern and maximum air and side-to-side gaps are required to prevent false alarms caused by shifting or warping doors and windows.