For Husqvarna Automower 450X/440/435X/420/330 Lawn Mower 2 RSWH-01 Spikes + 21 Self-Tapping Screws ?Provides Traction: When the lawn is wet or the ground has many inclines and slopes,the nails give the robotic lawnmower better traction,eliminating the need to dig in the lawn ?Built to Last: Made of high-quality plastic material,wear-resistant and durable,and the right size to provide you with long-term service ?Easy To Install: Just center the spike on the wheel and secure it with the included screws ?Beautiful Lawn: High-quality spikes ensure a beautiful lawn. No more holes in your lawn with your lawn mower robot ?Compatible with: ?Husqvarna Automower 330 ?Husqvarna Automower 440 ?Husqvarna Automower 420 ?Husqvarna Automower 435X AWD ?Husqvarna Automower 430X ?Husqvarna Automower 435X ?Husqvarna Automower 450X ?Husqvarna Automower 450X Compatible with: ?Husqvarna Automower 450X Package included: ?2 x Spikes ?21 x Self-tapping Screws ?1 x English User Manual ?Other things not included