I just bought 4 of these (2each in 2 sizes) just to have aboard, but I already have a few uses in mind. Colligo Marine also sells them for much more $. I have some 3/16 Amsteel at home and was planning to splice my own after seeing them on the Colligo site, but stumbled on these for under $10 each. Seemed like a no-brainer to order some. I just received them today and they're just as expected (sometimes you don't know with eBay).

These would be great anywhere you need removable blocks or to hold the small Holt dinghy snatch blocks (I use the 40mm size to guide my continuous line furler). Would also be ideal to attach sheets at the sail clew (light and soft = safer for crew when the sail flogs).

See link below. I have no interest in the seller.