WITH STORAGE CASE: The thread insert kit comes with a compartmentalized storage case for easy organization and transport. 41-PIECE SET: The set includes 41 thread inserts in various specifications from M2 to M14. They can be used for low-strength materials such as aluminum. FATIGUE RESISTANT: With some elasticity, the inserts can evenly distribute the load on each thread, eliminate tooth deflection, absorb vibration, and improve fatigue resistance. EXTENDED SERVICE LIFE: For components that are frequently disassembled, the inserts can prevent thread damage, improve thread life, and increase wear resistance. GOOD CONNECTION: The thread inserts provide good connection performance, increase connection strength, and improve connection conditions.