This product is made of high quality with excellent rust resistance and long durability, which is designed to provide stronger traction for robot mower on wet or sloping lawns, avoiding slipping and affecting operation results. It is easy to install and not only improves mowing efficiency after use, but also protects lawn from damage and keeps it beautiful and tidy. This material is known for its excellent resistance, can be in long-term with moisture, soil and other environments to maintain a clean as new, Its excellent tensile strength and hardness also ensures that anti-slip nails are not easily deformed and worn out when subjected to repeated pressure and friction, thus prolonging overall service life, reducing frequency of replacement, and saving you maintenance costs. Tand have been carefully calculated and tested to that they provide effective traction without causing excessive damage to lawn. for Landroid Robotic lawn mower series S450i [WR101 SI] M800i [WR111MI] S300 [WR130E]