it's basically just a bar that feels kind of like clay...(the warmer it gets the more clay like it gets, it's quite stiff to start with)

it's about half the size of a bar of soap.

you use it with lubricant (usually just a waterless wash product or you can get specific lubricant) and basically once you have washed the car, you rub the clay bar over the entire painted surface and it lifts any bonded contaminants like road grime,tar and any other muck that doesn't come off with a normal wash...

if you rub your fingertips over the paint before and after claying you'll feel the difference.

once you have done this the results of any polishing are greatly improved

if you have a particularly dirty car you just keep kneading the clay bar to get a clean side, you'll be amazed at the crap it picks up , some marks take a fair bit of rubbing, but if you use plenty of lubricant it's a very simple product to use.

you can get a kit from meguairs which contains lubricant, or use the sonus bar with poorboys