Compatible with Contour 500 XT, Power Trim 500 XT, Mini Trim Auto, ST/XT/Plus XT Mini Trim, Contour 500/700 (PNC 9648596/7), Revolution 2000/2300/2500, Twist, and Edge. Please check your model carefully before purchasing to ensure compatibility. Package Content: 4/6/10 Replacement Line Spools for Flymo FLY021 Trimmer Spool. Made of ABS and nylon line. The trimmer replacement line spool is constructed from high-quality raw materials, featuring a durable ABS spool and flexible nylon rope, designed for long-lasting performance. Save time and effort with easy installation. Pre-wound spool allows for quick setup. Tool-free installation enables fast mounting and removal. Durable design provides extended use, reducing the need for frequent replacements. Precautions: During operation, strong centrifugal force and rapid cutting may occur. It is recommended to wear eye protection and long pants to avoid injury. This trimmer is designed for light weed maintenance and is not intended for thick or woody vegetation. Use appropriate blades for tougher growth.