1. The roughness of the inner hole is below Ra0.4, higher-finish, and no burr, to ensure smooth feeding.
2. Made of titanium alloy and copper. The thermal conductivity of titanium alloy is much lower (about 1/14 of that of aluminum), and copper helps quickly dissipate heat, which effectively ensures the thermal conductivity at the heatbreak, preventing the filament from melting at the heatbreak, greatly reducing the plugging possibility.