The Vintage Olympic Barbell Spin Lock Collars are a set of two unbranded collars made of cast iron, designed for weightlifting with a pair weighing 2.5 kg each. Some rust, but check out the copper plated wingnuts. These black collars feature a spin lock design. Perfect for adding a retro touch to your workout equipment, these vintage Olympic collars are a durable and functional addition to any home gym or commercial fitness center.