The Red-line extensions start with 32.5 millimeter diameter, 6061 T-8 "drawn" aluminum tubing. The tubing is engineered so that with its perfect diameter and wall thickness you get incredible high strength-to-low weight ratio. The holes are precision punched, then the tube is red anodized in and out, permanent laser numbered at 2 centimeter settings. The adjustment settings are held with a hard anodized aluminum collar tethered with a spectra line to a stainless steel pin. It comes with a beefy "Power-Six" super powerful 6:1 downhaul cleat with large diameter pulleys perpendicular for power, easy rigging and no crossed lines and an 8-plait, pre-stretch downhaul line.