7002            |    Glass in balls (other than microspheres of heading 70.18), rods or tubes, unworked.
7002.10.00   - Balls
7002.20.00   - Rods
7002.31.00     -- Of fused quartz or other fused silica
7002.32.00     -- Of other glass having a linear coefficient of expansion not exceeding
7002.39.00     -- Other