SPITBOARDS O-Ring Kit in 6 colors to match your style. 4 original O-Ring Bushings and 4 Stainless Steel Washers are included in each set. SPITBOARDS are constructed from a sturdy, enduring, and tear-resistant material that works well and lasts a long time as well as allows for better control and maneuverability, while also reducing noise and vibration. Compatible with all fingerboard trucks, including ,Teck Deck trucks, FlatFace Dump Trucks, Dynamic Trucks, Blackriver Trucks and Y-Trucks (remove washers to use on Y-Trucks). For small and medium trucks, use the complete kit. For loose trucks, take out the washers. CHOKING HAZARD: Small Parts. Not suitable for children under the age of 14. SPITBOARDS products are designed and manufactured for teens and adults alike. Products contain small parts and are not safe to be put in your mouth due to the materials and choking hazards they represent. Please keep all SPITBOARDS products out of reach of children under 14 years old.