Black Guitar Lock nut 42mm For FLOYD ROSE Tremolo Double Locking System For Double Lock System Bridge it can be used in other designs also. Musiclily 42mm Guitar Metal String Lock Locking Nut for Electric Guitar 42mm Black Guitar Lock Nut for Floyd Rose Tremolo Bridge Black Package Included: 1 x Locking Nut 42MM 1 x Spanner 2 x Screw