INCLUDES: 4-inch to 3-inch dust collection reducer (1pc) FUNCTION: This dust collector attachment possesses a 4-inch OD end that connects to standard 4-inch ID dust collection hose and allows you to step down to a 3-inch dust collection hose or line branch. ? Note: to connect to other 4” OD ports or adapters, a 4” flex cuff, POWERTEC 70149, will be needed. APPLICATION: Designed for dust collection systems. Also suitable for dryer vents and laser engravers when exhaust temperatures remain within the ABS material’s recommended range (up to 176°F / 80°C). PREMIUM QUALITY & EASY TO USE: Made with heavy-duty ABS plastic for long-term durability and features a 4” OD profile with a tapered port on one side that fits inside most 3” dust collection hoses. DIMENSIONS: 4-Inch O.D nominal end (measures 3-15/16”) | 3-Inch O.D nominal end (measures 2-31/32”)