Compression-Style Tube Repair. Fast, economical tube repair. Repair pinhole leaks, cracks, kinks, and rub throughs with SPLICE-LOK(r) in air conditioning, coolant, transmission, oil, or fuel lines. For use with both 5/8 and 3/4 lines in any combination of those sizes. Not for use in brake or clutch systems. - Permanent Leak Repair - Saves Time & Money - Use Standard Hand Tools - Straight or Reducing - Steel/Aluminum/Copper.