Mercer Industries 671400 Diamond Blade for Porcelain Tile, 4-Inch 4-Inchx.060x7/8-Inch, 20mm, 5/8-Inch High diamond concentration - allows the blade to last longer and increase efficiency Tensioned and balanced - no wobble when using blade Steel core with proprietary diamond bond High diamond concentration Special bond construction Tensioned and Balanced Hot pressed technology No wobble while using blade High diamond concentration Special bond construction Tensioned and Balanced Hot pressed technology No wobble while using blade