If you're looking for a durable and versatile lock, the 40 mm model with a 20 mm brass shackle K5UD from IMNASA won't disappoint. Its brass construction is ideal for withstanding exposure to moisture, making it a great ally in marine environments. Plus, it comes with 5 keys, perfect for spares or sharing with your crew. Remember, the little details make a difference in onboard security, and this lock combines practicality, durability, and a compact design that adapts to multiple situations.