PYREX Reusable Media Bottles - dotscientific.com. Vented, GL45 caps with 0.22 µm PTFE hydrophobic membranes (Cat. No. 1395-45LTMC) w. Open Top, PBT caps in GL25, GL32, and GL45 sizes. w. Silicone or PTFE-faced Silicone Septa for the open-top caps. PYREX ® Reusable Media Bottles. PYREX reusable laboratory bottles are designed as storage