Petzls RAD LINE 6 mm Ultra-light and compact hyperstatic cord, designed for skiers doing crevasse rescue, rappelling or roping up on a glacier to traverse a crevasse zone. Designed for skiers, the RAD LINE 6 mm is an ultra-light and compact cord for crevasse rescue, rappelling or roping up on a glacier to traverse a crevasse zone. It is hyperstatic and flexible, and features a rough-textured sheath, for excellent handling and easy manipulation.