8' 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" True Value #770956, True Value #773125, Bracket Spacing, Screws For Attaching Rail Are Packed With Brackets (Order Separately), Meets ANSI/BHMA A156.14, Grade 1 Specifications.