Ultimate 420Ultimate 420 The Ultimate 420 U lock combines ABUS security technology and compact design into a lock that will make thieves tear their hair out. Ultimate 420 COMPACT, SOLID AND SECURE The Ultimate 420 radiates a feeling of security through its appearance alone. There are locks and then there is the Ultimate 420. If you are looking for a shackle lock that will deter potential thieves just by looking at it, then you don't have to look far. Thirteen