All VIPER® Couplers Sort by NewestSort by Name Price: - Air Duct Cleaning Equipment (3)VIPER® Couplers (3)Reset Filters VIPER® Large Barb Coupler, 3/8″ VIPER® Large Barb Coupler, 3/8" VIPER® Small Barb Coupler, 1/4″ Barb VIPER® Small Barb Coupler, 1/4" Barb VIPER® Threaded Coupler, 1/4″ NPT, Male VIPER® Threaded Coupler, 1/4" NPT, Male