Detailed Product Description

1. Whole glass vacuum tubes adopt super hard borax and silica glass;
2. Absorb rate: ≥ 93%, thermal radiation rate: ≤ 6%(100 degree)
3. Temperature when exposed to sun without water: 250degree, 2.5hours to boiling if using single tube;
4. Resist 25mm hail, using life can last 20 years.