I'm selling these because they didn't suit me, even though I installed and used both of them. I used them for a while, but there's no visible deterioration. All screws are included. If you'd like to purchase them together with other guitar parts I have for sale, please feel free to ask. Here's the official description: Dynaguide String Guide, White ■ Dynaguide ■ White ■ Moving string guide Provides stable tuning by moving with the strings. ■ Can be installed on standard Stratocasters and Telecasters without major modifications. ※ Includes one screw. ※ Some modification may be required depending on the guitar's condition.