This ugly CAD screenshot illustrates the general idea behind the Fruehauf wedge, straight floor and Trailmobile Build-a-Pup kits. There are several nose and body options that appear as separate colors here but are combined with a roof to make a single part for ease of assembly. Along with different styles of floor parts featuring landing gear and suspension options and a door frame part covering bumper and door style options it is possible to build any of a number of straight floor Fruehauf pup trailers.