I thought perhaps looking at the patents might help answer your question, but I changed my mind about doing the research upon retrieving them. Quite large. htt

I thought perhaps looking at the patents might help answer your question, but I changed my mind about doing the research upon retrieving them. Quite large. https://patents.google.com/patent/US7921211B2/en https://patents.google.com/patent/US7921211B2/en https://patents.google.com/patent/US7418504B2/en https://patents.google.com/patent/US7418504B2/en