The present invention relates to a process for preparing ethylene urea in solid form, in which a water-comprising product melt of ethylene urea is cooled on a breaking-up apparatus and the water content of the solid obtained is from 5 to 15% by weight. The power swivel is configured to mount on direct push equipment, such as a cone penetrometer, to eliminate the need for a conventional drilling rig when a consolidated layer is encountered during direct push operations. A rear lateral support assembly includes a support frame attached to a rear portion of the frame base such that the support frame is movable in concert with the frame base. A cover is placed around the pin and sealed to provide a fluid-tight enclosure that maintains reduced pressure around the pin. The fiducial markers then are aligned in standard image processing or image analysis software with simple image translation and rotation operations, without the need for more advanced scaling, distortion or other operations. 15%, a mean light reflection factor on the rear face in the visible region Rv lower than or equal to 1%, a mean reflection factor RUV on the rear face between 280 nm and 380 nm, weighted by the function W defined in the ISO 13666:1998 standard, lower than 5%, for angles of incidence of 30\xb0 and 45\xb0, the antireflective coating outer layer being a silica-based layer.