... 2. External used against breeze 3. No need electronic 4 Recyclable material Main MaterialMetal frame (aluminium, stainless ... , strike, water, snow, acid, alkali etcEnvironmental-protection, energy savingResistant to pressure, strike, water, snow, strong UV, ... . Environmental-protection, energy saving5.The 3D extrusion body enhance outstanding advertising effect6. No need any electronic, ENERGY SAVING