Cheap And Discounts COF&Silane, (1,3,6,8-pyrenetetrayltetra-2,1-ethynediyl)tetrakis[trimethyl- Wholesale. Buy Directly From Merchant Shop1104308565 Store. Enjoy ✓Free Shipping Worldwide! ✓90 Days Buyer Protection. ✓Easy Return. ✓Money Back Guarantee.