The "Ultra Tight" serie is 2 times stronger than the previous roof bolt products. The truss-shaped open legs can offer a wide range of supporting force to the thin steel plate. The washer and the bolt part of "Ultra Tight" are made of stainless steel carrying high corrosion resistance. The sleeve part is made of steel with Zinc-nickel alloy plating. The feature of "Ultra Tight" is that operators can use it with impact drivers sold anywhere in the market.