This black fitness pin with pull pin and spring knob is a practical spare accessory for fitness equipment. It provides quick, reliable locking for adjustable components on fitness bikes and related machines. The pin has a 25 mm diameter for compatibility with standard holes used on many devices, making it a useful replacement or backup part. Key benefits Fast, tool adjustments: pull the pin to release and reinsert to lock, with a spring knob to assist quick operation. Secure positioning: when engaged, the pin locks into place to prevent unwanted movement during exercise. Maintenance ready: a spare part designed to reduce downtime when a pin or knob wears or is misplaced. Clear identification: black finish offers good visibility and ease of identification among other components. Size fit: diameter 25 mm ensures compatibility with devices that require a 25 mm pin. Key attributes Functionality: pull pin with spring knob for quick release and locking of adjustable parts. Compatibility: intended for fitness equipment that uses a 25 mm diameter pin. Size: diameter 25 mm. Color: black. Performance: designed to provide reliable engagement and ease of maintenance as a spare accessory. Material: material details are not specified in the listing. Use cases Replacing a worn or missing pin on a home or commercial fitness bike to restore adjustable seat or handlebar positioning. Securing attachments or adjustable components on multigym machines that rely on a 25 mm locking pin. Serving as a spare replacement part for gym equipment to minimize downtime during maintenance or part replacement. Notes This description reflects the features indicated by the product title: a black pull pin with spring knob for fitness use, diameter 25 mm, offered as an exercise spare accessory.