Flexible rubber port adapters easily conform to irregular-shaped ports. Smaller inside diameters fit the dust hose onto an even wider variety of tools and the opposite end of each port threads securely into the stretch house. Compatible with Universal Small Port Hose Kit (sold separately). Flexible rubber stretches slightly and conforms easily to oddly-shaped ports. The other end of each port threads securely into the stretch hose included with the Universal Small Port Hose Kit. Hose Port 19mm (3/4") ID x 31.8mm (1-1/4") OD. Hose Port: 31.8mm (1-1/4") ID.