Very high quality lubricant works well on caliper slide pins and will not damage rubber boots. Also ideal for lubricating brake pad parts. A little goes a long way, and good lubrication of the brake parts is extremely important. This allows the calipers to open and close freely and easily. This ensures even wear of the brake pads and a longer service life of the pads. There are some other lubricants that work just as well, but very few of these will not damage wellies. Brake work with torn rubber boots will mean headaches and a trip to the auto parts store in the future.