We have 2 Tripp Trapps--one American market one and a German market one. Neither one has a "high back" adapter. The American one has a plastic rail that snaps on and a harness. The German one has a wooden rail and leather strap like the PP mentioned. Personally we only used the rails and rarely used the harness. It's doesn't really tighten or ride properly on the child so I think it's more of a danger than anything else. I really like the rails though.
8/28/10 at 12:33pm