This holdfasts are designed for model boats in two scales: - 1:32 (outer diameter of live belt: 25mm) - 1:16 (outer diameter of live belt: 35mm) - 1:10 (outer diameter of live belt: 50mm) Sadly you can always buy the life belts without holdfast. So I have designed this part to install the belt faithfully. After printing, I painted the part in silver.