Top of Boom Outhaul System using Allen 20mm Dynamic Tii blocks. Primary line is 3mm SK78 Dyneema in dark grey and a range of colours. The standard 4mm secondary control line rope is SK78 Dyneema cored/Polyester covered Robline Dinghy Control, or you can choose the premium Polytech line which is harder wearing with a Technora®/ Dyneema® cover. Finally, choose the length of line for the handle type that you like to use. If you want the system optimised for the 4.7 rig select that option under 'System Options' at the bottom of this page. Main photo shows system with dark grey primary and Control secondary line in green/white.