Product details:
Time Fastener Company Time-Sert 5561 BIG-SERT Oversized Thread Repair Kit, 5/16-18 Size 5/16-18. Insert length .450 These kits are used for threads which have been previously repaired. These kits will repair holes that were repaired by Helicoil, Perma-coil, Uni-coil, Recoil or any other similar coil style insert that has failed.