The Adaptor Chain from ABUS makes it really easy to make your bicycle twice as secure! Simply place the chain around a fixed object, pull the end with the lock through the ring on the chain and attach it to the built-in lock on your frame. You won't not need an extra key, nor will you need to lock the shackle separately. This great product is designed for use with ABUS frame lock 5950
or Abus Frame Lock SHIELD Plus 5750L
but also works almost every brand of built-in lock.