Riva's race proven Pro-Series Sponsons will dramatically improve the handling of your craft with their superior blade & backing plate design. Includes a bulletproof mounting system that features a solid backing plate and five anchor points with billet inserts in sponson fins. Sponson depth is adjustable to control the amount of influence they have on the craft. Easy installation uses original mounting studs. Includes necessary hardware and installation instructions. Fits all 4-TEC models with fixed stock sponsons.