traction: When the lawn is wet or the ground falls with many heights and depths, the spikes give the robot mower better traction, no more digging in the lawn. With our Husqvarna, you prevent your lawn mower from building up and getting stuck in the lawn. Top quality material: our cleats are stainless steel. A material advantage is that the cleats are stainless and therefore durable. Dimensions: 255 x 2mm. Additionally, 21 stainless steel screws are included. Easy to install and beautiful, healthy lawn: just center the spikes on the wheels and secure with the included screws. Premium spikes ensure a beautiful lawn. No more holes in the lawn while driving your Husqvarna robot mower. Great compatibility: with 255 mm wheel size, compatible with Husqvarna Automower 420 / 320 / 430X / 440, made of 2 stainless steel, 5 mm, deburred, scope of delivery: 2 x spikes, 21 stainless steel flat head screws.