Each of the jax is made of 100% borosilicate glass, making it more durable and allowing it to evenly distribute heat for an improved smoking experience. Keep ash and herb out of your hits and enjoy a cleaner toke with these Small Clear Jax Screens from Red Eye Glass®. Each of the jax is made of 100% borosilicate glass, making it more durable and allowing it to evenly distribute heat for an improved smoking experience.