Features: Quickly install spherical knob pull pin designed for simple assembly, compatibility with most bikes and exercise equipment, ideal for busy home gym enthusiasts seeking adjustments. Crafted with durability ABS and reinforced iron cores, this bike ball head pin ensures safe locking during intense workouts while offering ergonomic comfort for repeated use. Perfect for both casual users and professional trainers requiring frequent resistance adjustments on bikes, exercise bikes, and multiple gym setups. Enhances indoor cycling or gym routines with vibrations resistant stability, suitable for high intensity interval training and commercial fitness centers. Features a sweat resistant rotate mechanism and universals compatibility, delivering professional durability for seamless bike accessory upgrades. Specifications: Color:Four Choices Dimension:5.5×6.5cm/2.17×2.56in Component:ABS+Iron Package Includes: 1pc Spherical rotary pin pulling spring knob note: 1.Please allow 1-2cm errors due to manual measurement, making sure that you will not mind before order. 2.Due to the differences between different monitors, the picture may not reflect the actual color.