A transparent conducting layer deposited on the surface of a cathode-ray tube (CRT) that allows the surface charge to leak away, thus reducing the ESF (electrostatic field) to negligible values. The high accelerating voltage (14–25 kilovolts) of CRTs can produce an electrostatic charge on the surface. This is analogous to the charge produced by friction with highly insulating materials. It is claimed by some experts that this can be harmful to users. There is currently no consensus as to the levels or exposure limits that should be enforced.