Omega Scallop Nuts are tapered along their narrow orientation and straight-sided along their width to fit both curve and straight sided cracks well. Set 1 includes: #1, #2, #3, #4, #6 Set 2 includes: #8, #9, #10, #11, #12, #13 Features: Scalloped edges fit over small crystals for a better fit than other styles The smaller sizes will deform slightly under load to provide an even more secure placement Each head is machined from extruded aluminum, than anodized and color coded for quick identification