Acculign dual eccentric rearsets (US patent #6688629) offer an unparalleled fineness of adjustment due to their ability to be positioned, both vertically and horizontally, at infinite gradations within an area defined by the dimensions of the two eccentric offsets.  For example, rearsets with a simple bolt-hole pattern for adjustment offer a variety of positions at fixed increments (12mm up, 12mm back, etc.); and rearsets with a "single" eccentric adjustment offer infinite positions on a fixed circumference.  With a bolt hole pattern, you can position your pegs up, back, up and back and so forth, but only in predefined increments. You might not be able to go back and "a little" up, for instance.  With a single eccentric adjustment you can never make a horizontal movement without making a vertical one, and vice versa.  If your pegs are in the highest position, and you would like to move them back, you are also going to move them down.  These limitations are greatly overcome with the use of two overlapping eccentric offsets. Through the manipulation of two offsets, both horizontal and vertical adjustments can be made independent of each other, and at infinite gradations.  All of Acculign's D-E rearsets are supplemented with a five position bolt-hole pattern, which, in conjunction with the dual eccentric adjustment, allow the pegs to be placed at any position within an area of approximately four square inches.