Specifications Fiberglass FRP Rectangular Square Tube 1.High strength. 2.Anti-corrosion. 3. Anti-aging. 4. Anti-UV. Fiberglass FRP Rectangular Square Tube GRP Square tube is thermosetting plastic products combining the reinforced material of glass fiber roving, fiberglass mat and polyeste with resin , comparing with metal profiles , there are good features: 1. High strength.2. Low deformation rate.3. high HDT.4. Low Hydroscopicity.5. low thermal insulation coefficient. 6. Anti-corrosion.7. Anti-aging, insulation, anti-theft.