Official Floyd Rose L Shaped Fat Brass upgradable Sustain Blocks for Floyd Rose Tremolo units. Studies have shown that Mass = Sustain. The all new Fat Brass "L" shaped sustain blocks by Floyd Rose have been specifically designed to take advantage of the unused area under the tremolo arm. By incorporating an additional "L" shape of brass to the design of a stock sustain block, Floyd Rose has been able to utilize this previously unused space for additional mass which equates to more sustain and additional tonal qualities of brass.Brass has been a much desired material for guitar luthiers dating back to the invention of the instrument; it is notorious for increasing warmth and clarity simultaneously, a rare combination. While greatly strengthening chord clarity and beefing up individual notes, it also greatly improves resonance, especially in the midrange of the instrument. All of these improvements are accompanied with the undeniably?vintage sound and feel of this time-tested material.Since this block is larger than a conventional sustain block, it can also limit upward travel of the tremolo and can be set to rest against the body in a blocked bridge configuration. For floating bridge setup this block may require some routing in the spring cavity.These blocks will fit the Original Series 6 & 7-string, Special Series & 1000 Series 6-string, and the 1000 Series Pro 6 & 7-string tremolos.