Tripp Lite's T1, RJ45-RJ45 , ( RJ48C ) Cross-over Patch Cables are constructed with premium Quabbin 9720, T1 certified cable. Two individually shielded, 22AWG, 100ohm pairs, maximize the performance of your expensive T1 circuits and equipment. Beware of generic T1 patch cables made with inexpensive Cat5 unshielded patch cable. The American National Standards Institute ( ANSI ) states in ANSI T1.403 that T1 cable be constructed of two balanced pairs, 22 AWG Solid conductor, 100ohm impedance, with a loss budget of 5.5db. Cross-over wiring configuration available in 0.91 m (3-ft.), 1.52 m (5-ft.), 2.13 m (7-ft.), and 3.05 m (10-ft.) lengths. Custom lengths available...consult your reseller. Also available in Straight-through wiring configuration...see Tripp Lite N265- Series T1 patch cables.