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 Package included: 2 x Spikes 21 x Self-tapping Screws 1 x English User Manual Other things not included