These are custom transformers built out of knex. I use the movie designs to model them out. Took a long time to get them just right. Each one of them fully transforms and doesn't have to be taken apart to do so. They are a lot larger than their toy counterparts.
Here is my youtube homepage link to see Ironhide and Bumblebee transform [link]
Also some are posted at Instructables on how to build them here [link]