Compatibility: Compatible with eufy Robot Lawn Mower E15, E18 and C15. Contains: Blade Set (9 Blades + 9 Screws) ×3. Quality Materials: Made of superior high-carbon steel for improved performance and smooth cutting. Recommended Usage: Replace every 240 hours for optimal performance. Note: Wear gloves when changing the blades. Use Official Accessories: Authentic eufy accessories extend the lifespan of your robot lawn mower and come with official after-sales support.