This mod allows you to use the vanilla shulker box duplication glitch, making you able to have an infinite amount of items. Make sure to hold a pickaxe when performing the glitch

Every dupe action ('Dupe All' and 'Dupe') depends on your ping and may not always work correctly.

The 'Dupe' button will always dupe the item in the first shulker box slot. (slot id 0)