This rectangular aluminum frame is designed to carry Helmholtz cables for use with SC22 and SC24 magnetic field cancelling systems in SEM installations where there are no suitable walls for room cables. The frame is placed around the microscope column and stands on the floor around the vacuum console. The height of the middle bar is adjustable. The frame can be levelled and made stable by adjusting the feet. All joints of the frame are insulated so that no conducting loops are formed. This prevents currents flowing in the frame that would compromise cancelling system performance. The frame is available in three ranges of custom sizes. The required size should be specified when ordering.