Modular tool storage systems consist of interlocking or stackable components that form a single storage unit for holding and transporting various tools and supplies. Components can be added to or removed to customize the system. They are not interchangeable between different system brands and models. DEWALT TSTAK handles most tool storage and transport needs, especially when working indoors or in dry weather. DEWALT Tough System offers a wide variety of weather-resistant components. Milwaukee PACKOUT has multiple configuration options and offers a mix of weather-resistant, hard- and soft-sided cases. Klein MODbox provides various vertical and side-locking components to form a mobile workstation.