Knuckle joint allows 360° axial rotation and 15° angular offset, and has an internal pressure seal capacity throughout the tool's rotation. The spherical structure provides rotation and angular offset of the knuckle joint, while the seals in the tool provide sealing capability. The knuckle joint provides additional flexibility to the tool string, allowing for flexible rotation and angular offset when borehole is constrained and branch operations occur. Large diameter design allows the hydraulic activation control tool to be connected below the knuckle joint. The same coiled tubing string can be connected to multiple knuckle joints for simultaneous use.