The Klick and Ride, Grass Stud (Long) is manufactured using high quality German stainless steel and measures 25mm. These studs are resistant to rust and require low maintenance. Designed for soft surfaces and sub-surfaces this stud will function well in grassy, meadow/field, and muddy terrains. Care and Maintenance - To keep your Klick and Ride studs in top condition perform the following after each use: Rinse with water to remove soil and pat dry Spray lightly with oil (WD-40) or similar and pat dry Store in Klick and Ride case