Trem-Stabilizer Tremolo Stabilizer Machined out of solidbrass it has 2 tension weals one for extending the shaft to make a solid contact with the Sustainer block and one for the spring tension. This unit comes with a top locking screw to stop the tremolo from going backwards or down Two wood screws are included http://www.apollomusicparts.com/wp/wp-content/uploads/2023/06/trem-stabilizer.webm