XENA makes use of a stronger double-locking lock on the disc-locks because it is stronger than a regular lock and provides more security. In a default disc-lock, the weakest point is the locking pin. With the double-locking system, the body and locking pin is combined into one metallic piece of the lock, making it almost impossible to break the lock by any method.
The XENA double-lock technology can withstand up to amazing amounts of hammering and wedge attacks and still has its stable foundation. It has been tried and tested by professionals thru excessive force applied in breaking the lock, but to no avail.