Review on AUSTOR Pieces Mounted Abrasive Grinding by Dhoal Shankar

I read other reviews (different stones) that said they were loose. I almost bought orange stones (alumina?) but read a review that said they don't wear out too quickly. the purple stones look like finer sand, but they sharpened my little secateurs with little effort and didn't wear them down at all. They "DO NOT swing" and leave a nice "fine" finish. I originally wanted large barrel stones for my Dewalt hedge trimmer but I'm so glad I bought these little gems. This one stone will probably give me 15x sharpening (maybe more). What offer! All negatives can be a barker.? or competitor?