Our 13 mm. Double Rail - 3.5" is aluminum rail, featuring a tough clear anodized finish, to protect against oxidation in the harshest indoor/outdoor conditions. Standard rail length is 196.85 in. (5 m.), can be cut per customer request.  This keder rail accepts 10 - 13 mm. keder. Call (888) 727-7050 or Contact Us for a Quote on purchase and bulk options