This kit is for stiffening the rear fender arch area of the 914. It is made of galvanized metal, so they won't rust. Precision cut with plug welds cut so that edge welds aren't necessary. We engineered this kit based on our experience restoring and modifying the 914. This kit requires less fitting and less welding. A targeted approach that doesn't add unnecessary weight. Sold as a pair. This area often will crack due to fatigue at the apex of the arch. Many think that you need the multi-piece stiffening kit - however those kits have long been questionable regarding their efficacy. This rear piece is well worth it, as even street cars can develop stress cracks in this area. Each piece weighs just 820g or 1.8 lbs.