ESC (Easy Safety Clip) is a safety release system for mudguard stays developed by SKS GERMANY.
If a foreign object becomes trapped between the tyre and the mudguard while riding, the mudguard can be placed under heavy stress. Without a safety release system, in the worst case the mudguard could be pulled towards the tyre and block the front wheel.
The safety system reduces this risk: the mounting adapters at the ends of the stays are designed as two-part components that are fitted into one another. Under heavy load, they can release from each other in a controlled way. This separates the connection between the stay and the bicycle frame or fork.
The ESC base units are available as spare parts in the OrangeStore.
The video provides a clear demonstration of how the ESC safety system works.