This is a 2oz bottle of Team Associated 50wt (650cSt) silicone shock oil used with oil filled shocks. Team Associated shock oil is made from 100% pure silicone oil and will not thin out in hot weather or thicken up in cold weather. The higher the weight number of the oil, the thicker the oil is. Team Associated shock oil is generally slightly thinner than Team Losi shock oil with the same 'weight' rating.