Pakcage：Hole saw diameter: 3-1/2"（90mm）; 1x 220mm sds plus connecting rod; 1x 110mm center positioning drill bits; 1x positioning drill screw Material: The concrete hole saw kit made of tungsten steel and alloy, high-frequency welding technology, welding openings is very strong, smooth inside and outside welding mouth. Ultra-sturdiness and durable, easy to opearation, and long service life Wide applications：The masonry hole saw bit set fits sds plus shank on the connecting rod works with sds plus tools by all major manufacturers. Easily drills walls, stones, bricks, or installation of air-conditioning, oil fume exhauster, sewer pipeline hole open and so on Tips：Since the hardness difference of the stones/bricks, hole saw need a bit more time than normal, please use it with flowing water when work on high hardness material, it will reduce the abrasion of the hole saw Unique design：The masonry hole saws blade is made of raw materials, thicker and sharper than other ordinary blades. It can easily penetrate steel bars up to 6mm A+