The red urathane bumper is the spring, so it does have a spring, a red urathane spring.
For those that have one... How much angle difference between the truck and trailer can be had? The red bumper is short, so the spring travel will be small, and when it bottoms out that is it. With bar springs they will keep bending or the trailer frame will bend, but mostly the spring bar will bend as needed.
Or what happens if you go too far? Will the bolt-on mount just twist forward and no harm other than having to re-set it?