IBM Quantum has demonstrated four meter-scale cryogenic L-couplers linking two full 120-qubit IBM Quantum Nighthawk R1 processors, achieving an average inter-chip quantum state transfer fidelity of 99.00% (best link 99.29 ± 0.07%) and distant CZ entangling gates averaging 94.75% fidelity. The 80 cm aluminum-aluminum coax lines with low-density PTFE operate near 5 GHz and use perpendicular indium-to-indium pressure bonds mounted after the modules are secured in the cryostat; they survived three full thermal cycles without degradation. A loss mechanism was identified: ambient magnetic fields during cooldown trapped flux, dropping the internal quality factor Q i from 1.5 × 10⁶ at zero field to 2.5 × 105 at 14 Gauss. IBM mitigated this by jacketing the cables in multi-layer high-permeability magnetic shielding, preserving Q i near 10⁶. The work validates the physical backbone needed for the planned 2029 IBM Quantum Starling fault-tolerant processor. 1