The Spine Clamp Kit B0000586 reduces booklet corner tearing when making very thick booklets. All saddle-stitcher side-knives normally result in some tearing of the book spine corners as the V-shaped spine is not supported well by upper clamps. The clamp kit modification ensures that the V spine is better clamped to reduce spine corner tearing by the side knives.
The standard modification
kit is designed to suit A4 or 8½ x 11" finished book
sizes only. For other sizes refer to IBIS.