Hexagonal Shaft Design: 4.5mm OD to the side and 5.0mm diagonal, providing large, medium and small rocker options, large size fits 6000-7000 models of fishing reels, medium size is suitable for 3000-5000 models, and the small size is tailor-made for 1000-3000 models. All-metal Construction: The all-metal rocker arm has excellent strength and can maintain stable performance even under high strength use. Right & Left Handed: The rocker arm supports left & right-handed interchangeable design, no matter you are left-handed or right-handed, you can adjust it according to your personal habits to ensure a smooth hand, and enhance the comfort and efficiency when fishing. Convenient Installation: The metal hexagonal torso design allows you to quickly install and fix the rocker without the need for additional tools, and firmly locks onto the fishing reel.