1)The bike cleats and two of the washer are made of stainless steel, wear resistance, anti-corrosion and high hardness 2)Screws and the other two washers are made of CRMO, having resistance to heat, corrosion and impact. 3)Compatible with Look system mountain bike pedals; NOT compatible with Shimano SPD system 4)Package included: bicycle cleat*2; stainless steel washer*2; CRMO washers*2; screw*4; allen wrench*1