FIRESTIK Heavy-Duty Spring Plated Steel. Features/Specifications: B Radio Antenna Spring Chrome Plated Heavy Duty 3/8In X 24 Antenna Threads For Antennas Up To 60In Tall Spring Is About 3In Tall Features of FIRESTIK Heavy-Duty Spring Plated Steel: B Radio Antenna Spring Chrome Plated Heavy Duty 3/8In X 24 Antenna Threads For Antennas Up To 60In Tall Spring Is About 3In Tall Package Contents: FIRESTIK Heavy-Duty Spring Plated Steel FIRESTIK R3H: Heavy-Duty Spring Plated Steel