These Adjustable Loads consist of a flanged section of straight waveguide containing a geometrically optimized absorbing element driven by a precision micrometer. There is more than one half wavelength of travel at the lowest frequency of each waveguide size. The micrometers used on these loads utilize a special dampening feature making the locking type of micrometer unnecessary. Our Adjustable Loads are available in sizes WR3 to WR42. WR3 to WR12 are electroformed, WR15 and above are made from extruded waveguide.