http://www.ems.com/search/r2_results.jsp

They're from EMS. They only give the size on one of them and it seems to be a little big. What's the diameter on the one's sold by REI? Is there an ideal size for one inch webbing and is the size really critical. Can you use different width webbing with the same set of descenders or is there a suggested size/ratio?

Thanks, Miguel