These Gas Performance shocks are far superior and longer lasting than oil filled shocks. Gas Charged Performance Shocks will improve the handling and stability because they adjust to varying road conditions while you drive. On smooth roads the shock piston travels freely for a comfortable ride, on rough road surfaces the shock piston compresses more rapidly and the shock responds faster to maintain tire-to-road contact. Gas Charged Performance Shocks are specifically designed and engineered for the Classic Volkswagen Beetle and Karmann Ghia.