We have 2 sizes of triangular spreader plates. The small ones are best for aerial straps and the large ones are best for dance trapeze. For hammock you can use either small or large. We recommend using the Trix triangular plate with Rock Exotica Shackle Swivels.
Small size: 7cm between the exterior bottom holes (centre of hole-to-centre of hole)
Large size: 11.5cm between the bottom holes (centre of hole-to-centre of hole)
The stainless steel triangular plates are for keeping the swivels apart to allow them to spin smoothly and without obstruction.