The POWERTEC O.D. Splice, 4-Inch, is designed to connect two 4-inch hoses together. Your dust collection hoses press securely over both ends of the device. The center area of the Splice is raised for ease of installation and more solid grip. Use in building, or expanding your dust-collection hose network. Fast and easy to install, these handy accessories maximize the efficiency and effectiveness of your dust collection assembly.