Check the listing for details. Button Head Screw For Rear Mount Floyd Rose Style Locking Nuts (2 pcs.) - Black. Condition: New. Listed at 1.60 USD. These screws are used to fasten a locking nut to the instrument through the back of the neck. This style of mounting has been featured on locking tremolo designs from brands like Floyd Rose, Ibanez, and Gotoh. In most cases, the neck is drilled on either side of the truss rod and the screw would be countersunk allowing for a discrete mount. At 16mm in length, these screws are about 1.5mm shorter than the 11/16" screws Original Floyd Rose nut mounting screws that are sold as SKU: FRNMSRBP. In our experience, they are plenty long enough for most applications. Specifications Button Head Cap Screw Thread Size: M4x0.7 Length Under Head: 16.0000 mm Material: Alloy Steel Key Size: 2.500 mm Finish/Coating: Black Oxide Professional installation is strongly recommended. Improper installation may result in damage to the product and/or instrument.