BIG-SERT By TIME-SERT 1/4"-28 UNF Oversize Thread Repair Kit # 5448 BIG-SERT is a heavy wall solid bushing, easy to install with positive placement. BIG-SERT gives increased load protection for critical use. BIG-SERT will repair oversize holes which have previously been repaired. This is a complete kit including: drill bit, counterboring tool, tap, inserting tool, and 5 inserts!