XL = 50ml bottle HUDY Ultimate Silicone Oils are manufactured in Europe by a specialized silicone oil premium manufacturer and were created exclusively for HUDY. Each batch of ultimate oil is laboratory tested and calibrated to ensure the highest possible consistency and quality from batch to batch. Based on the industry-proven cSt rating, the new line of oils will be easy to identify, adjust, and feel. HUDY oils cover the complete range from Ultra Thin (100cSt)... Thin (1000 cSt)... Medium (5000cSt)... Thick (10.000cST)... up to Extra Thick (1.000.000cSt), with numerous stages in between. Thinner oils are suitable for shocks (up to Medium), and thicker oils are suitable for differentials. With the available range, you will be able to find the correct viscosity you need for your application. Each category of oils is individually color-coded to allow you to instantly recognize the type of viscosity. Available in large 50ml and extra large 100ml bottles with convenient flip cap.