Steinberg Systems SBS-EH-500/3 Bedienungsanleitung Seite 48

Then measure the diameter of the material in the same area on a link that
does not normally pass through the lifting wheel (e.g. near the end of the
chain). Compare the two measurements. If the diameter is smaller by 0.25
mm or more, the chain must be replaced. The chain should be replaced by the
manufacturer's service or a qualified person.
Here are the dimensions of the chain links depending on the model of the
device:
• SBS-ECH-500/3