Material: These luggage sets with wheels are made from high tenacity PC material, harder and more resistant to pressure, effectively reducing damage caused by collisions during travel. We have perfected our hard case luggage collections, with high quality material molded body coveted. Instructions for Reset the combination lock 1.The lock is Pre set to 0-0-0; 2. Push the button on the broadside, while in this position, set each number to your preference; 3. Release the button and your combination is now set; 4.Take care when setting the numbers to not release the button while setting it.