The roller parts will help keep your guitar in tune better when bending strings or using a vibrato system. The bridge can be locked to the posts for improved sustain.specificationsbridgediameter anchor: 12mmlength anchor: 19,5mmthread studs: M8diameter studhole in bridge: 8x4mmspacing studs: 74,4mmstringspacing E-e: 50,4mmradius: 14"wire retainer: nosaddles notched: n.a.finish: chrome