LSDA heavy-duty padlocks are designed to meet special security needs. Our “key-to-match” series padlocks are designed to be compatible with keys that open door locks. The convenience of carrying one key, or the need to include padlocks in a master-key system or restricted keyway system call for these padlocks. LSDA SFIC series padlocks accept cores from various manufacturers. Padlocks are key-retaining.