LedgerLOK replaces lag screws and through-bolts, has been coated with a proprietary three-step coating process that protects against corrosion (even in pressure treated wood) and is ACQ approved. All LedgerLOKs will not to rust or corrode for the life of the project. The fasteners have also been tested and approved for use in ACQ including contact treatment levels. LedgerLOKs are not recommended for saltwater applications..