The Bont Electronic Bearing Cleaner spins the bearing and cleans out all the dirt, oil, and even mild rust. For example, simply slip your 688, or 608 roller skating bearing onto the cleaner. Dip it in your choice of non flammable cleaning solution, and press the red button. This is the easiest way to clean your roller skate bearings. It takes around 20 seconds per bearing to clean them. The bearing cleaner works with any brand of 608, 688 sized bearings. Get your roller skate bearings looking like new again. Fits all 8mm bearings.