The StopperGate is nessecary for using the the RopeGuideTwinLine in the SRT-Setup. It provides the trapeze to be crushed be the Cocoon. In the SRT-Setup the stationary rope is running through the Cocoon and the Trapeze. Behind an alpine butterfly knot follows, that not slips through the Cocoon and Trapeze. The StopperGate is clicked directly on the Trapeze.