1. the shell is bed up of engineering plastic with properties of impact-withstanding and corrosion-proof. 2. high efficient reflecting bowl. 3. the transparent b is bed by polycarbonate injection moulding. 4. it has focusing device, which can make adjustment of astigmatism and prefocus. 5. inner-lying switch, with the functions of good water-proof and dust-proof. 6. use special tools when maintaining, so that it is safe and is easy to dismount. 7. the curve-tube type is a kind of unigue design, and it is filled with buckle, which is convenient to carry and use and can elaborate the highest efficiency during the emergency. 8. suitable for GB3836-2000, IEC60079, GB12476.1-2000,IEC01241 standard request.
