Pretty handy. It's a little finicky, maybe because I'm on Linux, and gets "stuck" once in a while. Sometimes I have to go log in to CapOne in another window before the extension will work. But very handy for keeping CC numbers separated and limiting the blast radius of an exposure. I especially like the ability to turn virtual cards off when not in use or at a future date - E.G. when signing up for a free trial service I do not intend to renew.