Kratos - 7m Length Helixon Retractable Wire Rope Fall Arrest Block - Vertical Use 7m7m Length Helixon Retractable 4. 5mm DIA Wire Rope Fall Arrest Block with Polymer Casing Vertical Use Only 7m (SKU 286 1520 23). High impact resistant polymer casing. x2 Swivel rotations. Smaller and lighter design. This Kratos Helixon Fall Arrest Block is approved for Vertical use only. For models approved for Vertical and Horizontal Use see the Helixon S models. Complete with swivel snap hook with load indicator at attachment end and karabiner at