... lamp, halogen light, high pressure sodium lamp. ItemSpec(mm)WT*L(mm) NW GW Flare TubeΦ13.5+/-0.31.2+/-0 ... .35+/-0.05*(1500)20211.35+/-0.05*(1500) Exhaust TubeΦ4.4+/-0.20.8+/-0.075*(1175)1717.80 ... borosilicate glass, hard glassUsage: Used for high pressure mercury lamp tube, halogen light tube, high pressure sodium lamp tube.