Element is a manufacturer of quality airsoft parts at affordable prices. These airsoft spring guides all have ball bearings, which reduce stress on your spring. We have the Element vortex spring guide for version 2 and version 3 gearboxes. The standard version 3 and version 2 ball bearing spring is available from Element as well. We also have an Element M14 spring guide with ball bearings.
The primary difference between the Element Vortex spring guides and Element's other spring guides is their material. The vortex ones are made out of metal, where as the standard ball bearing ones are manufactured out of polymer.
Ball bearing spring guides will work with most setups, but they are ideal for high stress setups.