PREMIUM BUILD: This dust hose coupler is made out of high quality ABS plastic, which is primarily known for it's abrasion resistance, high tensile strength, and long-term durability. FEATURES: Tapered ports on each end, a raised middle section diameter to provide easier assembly and comfortable grip. FUNCTION: Provides a secure, quick connection between two 4-Inch ID dust hoses - extending the reach and versatility of most standard dust extraction set-ups. DIMENSIONS: Dual 4-Inch nominal ends measuring at 3-31/32-Inch O.D. and 3-11/16-Inch I.D. - to accommodate all 4Inch ID hoses.