About this item DESIGNED FOR CONCRETE MASONRY ROCK - WELLYUK 6" turbo diamond cup grinding wheel designed for grinding concrete masonry, rock. Works great on Concrete Masonry rock stone surfaces SIZE - Outer diameter: 6 in. /150 mm, Inner hole: 22.23 mm( with ring adapters to 20 mm). WET/DRY USE - Turbo row segments with the 5mm segment height are perfect for both fast and smooth grinding. can be used in wet or dry state, great to use in different situations.adding some water, you get better effects during grinding. WIDE APPLICATION - Our diamond grinder wheel used for dry/wet grinding of concrete, granite, stone, marble, tile, masonry and some other construction material to smooth uneven surfaces and remove flashing MULTIPLE USAGE - It is suitable for most angle grinders and grinding machines. Please compare the relevant parameters of your machine (e.g. Inner hole) carefully before purchasing to avoid unnecessary trouble.