Modified windows German normal with reinforced top beam with straight side panels.
 Wood thickness: Top beam 19 mm, ears trimmed to 8 mm
 Width of top beam support: 25 mm
 Top beam: 394x25x19/8 Bottom part: 370x25x8 Side: 338x25x8
 with modified top beam with groove 19 mm thick
 eye and glued
 Frame width 25 mm