This trailer is based on the 'Pitts' type, with an overall length fo 40, but easily replicates many types of similar trailers. It includes every detail I could think of, except for tires and DOT striping, so all the builder needs to do is add wheels and striping after painting. It also has a hitch on the back to pull a short trailer (coming soon!) to replicate a 40/20 configuration. The small bars between the bolsters aka bunks, are there only to help maintain straightness during printing, and help prevent breakage during shipping. Yes, they should be removed in the prep phase. This file has passed a number of software checks, so it should print in FUD of FXD without a problem. IF there is a problem or question, contact me via the shapeways link or via email to modelmechanic@gmail.com.