The 20mm stand up block is now standard in the Zim C420 as a lead for the boom vang control line. It makes a great upgrade from the former fairlead and can be used for a number of other applications...
The Opti Pro Vang features a dyneema upper section for splicing to your boom which helps minimize the amount of stretch in your Optimist boom vang system. It also features a 6mm sprint cord control...
