Firestone Rubber Liner form Gordon Low Durable Flexible and Safe to the Fish and Plant Life MATERIAL APPROVAL SPECIFICATIONS BS903 - Physical Testing of Rubber WRc - Approval to BS6920: 2000 EN13948 - Root Penetration Test DIN 4062 - Root Penetration Test BS6906/4 - Puncture Strength ASTM G53-84 - UV Resistance 1mm Thickness