Wilson Combat Ultima-Lube II is a blend of petroleum and synthetic lubricants specially formulated to ensure optimal firearm performance and inhibit wear. The unique blend of lubricating fluids has proven ideal for today's high-tech semi-auto weapons, whether manufactured of conventional steel, aluminum alloys, or stainless steel. In addition, we have found nothing superior to Ultima-Lube II for the proper lubrication and protection of the hand-fit custom firearms that Wilson Combat is known for. Very low viscosity, penetrates hard-to-reach areas Ideal for extreme cold weather use Excellent for precision-fit firearms Recommended for tightly fit handguns of minor calibers (9mm, .38 Super, etc.)