With mounting screws. It is easy to install and fits perfect for your guitar and bass. Help to maintain the correct finger position. Reduce the strength required to play the instrument, relieve repetitive strain injury, help to alleviate the fatigue of long-term instrument playing. Guitar ​thumb rest, Bass thumbrest is plastic. A good replacement part for broken or old-one. smooth plastic cushion, provides extras thumb rest and for your hands and the instrument. Great accessory for guitar and bass instrument. You can freely set this part on the bass you want.