our Stripe Square glass tube , the above are the special sizes tubes, nomarl sizes are no problem We may also produce each kind of heterogeneous glass tube O.D 6mm-315mm borosilicate glass tubes and O.D 4mm-30mm for borosilicate glass rod: with 3.3 lineary expansion, good waterproof and acid-resistant ,for industrial, chemical, handcrafts&gifts purpose . Stripe Square glass tube