Replaces Standard Railmount Hardware. Allows Toolbox to be installed flush against BackRack(TM). Eliminates gap between Toolbox and Backrack. Allows Toolbox to be installed without drilling into truck bed. Standard 21 inches. Optional 31 inches available. Tonneau Cover Hardware Kit; Wide Top; 2019-2021 Chevrolet Silverado 2500 HD Extang - Solid Fold Extang - Trifecta Gator - Hybrid Gator - Soft Tri Fold Ionic - Tri Fold Lund - Genesis Tri Fold Pro EFX - Tri Fold Rugged Cover - E Series Vinyl Folding Advantage Truck Acc - Hard Hat Rugged Cover - Hard Folding American Tonneau - Hard Tri Fold Rugged Cover - Premium Vinyl Folding American Tonneau - Soft Rolling Tonnopro - Hard Fold American Tonneau - Soft Tri Fold Tonnopro - Tonno Fold BesTop - EZ Fold Trail FX - Soft Tri Fold Enthuze - Hard Tri-Fold Extang - Trifecta ALX Enthuze - Soft Roll RTX - Soft Fold Enthuze - Soft Tri-Fold Enthuze - Hard Tri-Fold Wide Top, 2019-2021 Chevrolet Silverado 2500 HD Extang - Solid Fold Extang - Trifecta Gator - Hybrid Gator - Soft Tri Fold Ionic - Tri Fold Lund - Genesis Tri Fold Pro EFX - Tri Fold Rugged Cover - E Series Vinyl Folding Advantage Truck Acc - Hard Hat Rugged Cover - Hard Folding American Tonneau - Hard Tri Fold Rugged Cover - Premium Vinyl Folding American Tonneau - Soft Rolling Tonnopro - Hard Fold American Tonneau - Soft Tri Fold Tonnopro - Tonno Fold BesTop - EZ Fold Trail FX - Soft Tri Fold Enthuze - Hard Tri-Fold Extang - Trifecta ALX Enthuze - Soft Roll RTX - Soft Fold Enthuze - Soft Tri-Fold Enthuze - Hard Tri-Fold Wide Top, 2019-2021 Chevrolet Silverado 3500 HD Extang - Solid Fold Extang - Trifecta Gator - Hybrid Gator - Soft Tri Fold Ionic - Tri Fold Lund - Genesis Tri Fold Pro EFX - Tri Fold Rugged Cover - E Series Vinyl Folding Advantage Truck Acc - Hard Hat Rugged Cover - Hard Folding American Tonneau - Hard Tri Fold Rugged Cover - Premium Vinyl Folding American Tonneau - Soft Rolling Tonnopro - Hard Fold American Tonneau - Soft Tri Fold Tonnopro - Tonno Fold BesTop - EZ Fold Trail FX - Soft Tri Fold Enthuze - Hard Tri-Fold Extang - Trifecta ALX Enthuze - Soft Roll RTX - Soft Fold Enthuze - Soft Tri-Fold Enthuze - Hard Tri-Fold Wide Top ...See Application Guide for Additional Fitments
