This is an insert for adjusting the height of the arm on a Jaguar/Jazzmaster floating tremolo. For those who want to set the arm position higher. After installation, the arm is held by the strong magnetic force of the neodymium magnet, so it will not come off even if you turn the body upside down. Installation method: Remove the tremolo block from the guitar and insert the neodymium magnet from the back of the arm holder (refer to the product photo). Adjust the insertion of the neodymium magnet to your desired arm height. Once the position is set, tighten it with the included tight lock and put it back in place. The arm height can be set from approximately 27mm or more from the tremolo block. Compatible with pop-in type floating tremolos on Fender Japan Jaguars and Jazzmasters, with an arm diameter of 5mm. The brand is registered as Fender, but it will fit other manufacturers if the arm diameter is 5mm and made of iron. Note: The arm holder in the photo is for reference only. It is not included. The product includes one neodymium magnet and two tight locks, as shown in the third photo. Do not hammer the neodymium magnet in, as this may cause damage. Gently insert it after slightly widening the opening of the arm holder. Serious accidents have occurred where children have accidentally swallowed neodymium magnets, requiring abdominal surgery. This product is not intended for use by children, so it should be handled by those aged 14 and over.