10', Galvanized Trolley Rail, Designed For Doors Weighing Up To 450 LB, Can Be Used With Many Types Of Single & Multiple Brackets, Galvanized Coated Steel, Use With 24" Bracket Spacing, Screws For Attaching Rail Are Packed With Brackets, Not Included, For Installing Single Rail Use TV #770-956, For Bracket Needed When Joining 2 Or More Pieces Of Track Together, Use TV ##773-125, Meets ANSI/BHMA A156.14, Grade 1 Specifications.