GB Racing swingarm spools provides the ultimate protection! The tough long glass fibered nylon is a high impact material that is designed to absorb energy without cracking in most situations. Injection molded 60% long fiber nylon swingarm spools provide the ultimate in protection for your machine. Secures directly into the motorcycles swing arm. Designed to be installed in the existing swingarm bungs. Anodized aluminium inserts allow a tight and secure fixing. Bobbins sold as a pair.