The 6mm Pack Washers suggests washers with a 6mm inner diameter or a size compatible with a 6mm bolt or screw. Kit refers to the inner diameter of the washer and is common for bulk purchases or when the washers are needed in larger quantities for specific projects. This is the standard way of specifying washer sizes, and it corresponds to the size of the bolt or screw it is intended to be used with. We make sure to provide a quality-tested range of 6mm Pack Washers, which can be availed at market-leading prices.