As I understand the challenge, we are looking for a California insulator that is as clear or clearer than a Pyrex CD 128. The Pyrex was chosen because they pretty much all come in clear (except for a few straw ones) and the clearness is at the extreme end of the continuum. Here then is my entry of a CD 160 which is clearly more clear than the Pyrex. It fact, it is so clear, it makes the Pyrex look brown! Rick Soller