Chalk Line was specifically developed for the punishment gyms inflict on rope. Whether you have a small gym or big wall the Chalk Line can take the constant falls, and belays. The Str8 Jacket Core allows the Chalk Line to hold its shape and keep the cover and core in balance which virtually eliminates sheath slippage. This will reduce flat spots and help maintain the performance of the over all rope. Chalk Line will provide a safe easy belay through a variety of devices while still maintaining its shape. / Weight: 9.7mm 62 g/m 10.2mm 68 g/m 10.8mm 77 g/m / Impact force: 9.7mm 9.8 kN, 10.2mm 9.8kN, 10.8mm 9.7kN / UIAA falls: 9.8mm 6, 10.2mm 7, 10.8mm 7 / CE and UIAA Certified