All bolt-on Multi-Latch systems will take a padlock with up to a 14mm (5/8″) shackle. While Dual Multi-Latch systems will work with between 7mm and 11mm (1/4″-7/16″) shackles, for larger shackles, the Dual Multi-Latch systems can be altered upon request to take up to a 14mm (5/8″) shackle.