In another posting I commented that to use them I need to replace the tarp split rings (going larger) and that they are clumsy on the wrong size cord. Looks to me like ideally they need 2mm cord that will wrap smoothly.
I got some and tried them with a tad pole and a superfly. I do think they are stamped and a little sharp on the one side so I'll have to smooth them out. Overall I really like the ease of use and lack of perusiks. I have the small split rings on the superfly and was able to get the toggles trough. With the shock cord they may be more mobile in the wind, one could probably use cordage and be fine. Overall simple to use and great idea I like em