Liqua-Lube is the first trailer hub lubrication system that uses liquid lubricants instead of grease. Liqua-Lube is a superior system that protects hubs and prevents breakdowns. Its clear cover lets you see the lubricant level, so you'll never run out of lubricant again. The Liqua-Lube System virtually eliminates dirt and water contamination in Marine Trailers-the major causes of bearing/hub failure. Liqua-Lube also eliminates the need for messy and expensive bearing repacks. The savings over annual bearing repacks can pay back the cost of the Liqua-Lube System in a very short time. Over 1 million miles of testing. The product is completely bio-degradable and doesn't require EPA regulated disposal like petroleum based greases that are often used on trailer hubs.