Here is a little graphic of the different sized Van Beest Green [Screw] Pin Bow Shackles carried by ASR.  Van Beest lists their shackle Working Load Limits (WLLs) in Metric Tons, which can be confusing to non-metric types - so we converted everything to lbs to help clarify.  The Green Pin Shackle WLL is based on a 6:1 Safety Factor, making the estimated breaking strength 6X higher than the WLL.