Keys Category F (ASSA 960) Explanation Keys to the ASSA 960 Features / Function Key length: 102mm 103-120mm 121mm - Keys Category C/D (ASSA 1919, 1920, 1924, 1925, etc.)Keys to the ASSA 1919, and others. Keys Category B (ASSA 704/709)Keys to the ASSA 704/709 Keys Category E (ASSA 1926)Keys to the ASSA 1926 Do you want to create a safe lock environment? ASSA OEM has created "The lock guide by ASSA OEM", and it's made to give you knowledge and tips about approved lock sets. We really encouring poeple to read our tips and guidelines here: The lock guide Want to download our product catalogues? If you prefer to download our product catalogue - you can download it here! We also provide instructions, declarations and other documents in our download documents section.Check it out!