Schaller Locking Low Profile Tremolo Chrome 5370 with R2 Locking Nut and 42mm tremolo block. All tremolo systems are supplied complete with nut (please choose R1-R10, see under "guidelines"), string retainers, springs, height adjustment screws, Allen wrench and mounting accessories. Available tremolo blocks in heights of 32, 37 and 42mm, but we order 42mm as standard Along with the tremolos and nuts, Schaller supplies wood screws and steel screws / Allen screws, so you can choose how to attach the nuts yourself i.e. either from the top or from underneath. The nuts are also specially designed so that you can use wood or steel screws without carrying out any modifications whatsoever.