IKN Black 42mm Guitar Metal String Lock Locking Nut for Tremolo Bridge Electric Guitar Double Lock System 42mm locking nut used for electric guitar Floyd Rose double lock system. Height adjustment of the strings at the neck end, can provide much better tuning stability and tone. Length:42mm.Width:15.6mm.Mounting Screws Hole Distance:14mm. Material:Metal;Color:Black. Package Includes:1 x Locking Nut,1 x Allen wrench,2 x Screws.