Extang Trifecta Toolbox 2.0 - 99-06 (07 Classic) Silv/Sierra 8' Model 93945Extang Trifecta Toolbox 2. 0 99 06 (07 Classic) Silv Sierra 8' Model 93945 Choose Simple: Extang's redesigned soft tri fold cover has a host of new features yet remains the easiest to install and simplest to use. The newly redesigned Trifecta 2. 0 Toolbox Series works with an existing standard 18 20" toolbox. Designed, manufactured and assembled in the USA! Your choice in soft tri fold covers is still simple! Works With Your Existing Standard 18 20