The Chase Sapphire Preferred Visa card has an aluminum core. Enough to block a Clipper Card signal 🙂 Shortlink:37.7897697-122.4190773Share this:Click to share on Twitter (Opens in new window)Click to share on LinkedIn (Opens in new window)Click to share on Pocket (Opens in new window)Click to print (Opens in new window)Like this:Like Loading... Similar Entries Twitter