DMI's new Torsion Restraint EXpress (T-Rex) System is the safest, fastest method of making sure arms and stops stay on the bar. The demands placed on today's arms and stops require the use of an additional safety device. We've all seen too many accidents caused by the right front stop being pulled off...NO MORE! All DMI torsion bars are now internal threaded and include T-REX threaded plugs for each end. The T-REX plugs utilize a 9/16' hex. The simplicity of one wrench makes bar changes a snap. Don't be the next video clip. Ensure your safety with the protection of a T-REX.