1)The frame is made of magnalium and the axle is made of CRMO, lightweight, anti-corrosion and durable. The spring on the bicycle pedals is tightly fixed and fastened. 2)Easy installation: L for left pedal; R for right pedal. 3)The bike cleats and two of the washer are made of stainless steel, wear resistance, anti-corrosion and high hardness 4)Screws and the other two washers are made of CRMO, having resistance to heat, corrosion and impact. 5)Package included: bike pedal*2; bicycle cleat*2; stainless steel washer*2; CRMO washers*2; screw*4; allen wrench*2 6)Compatible with Look system mountain bike pedals;NOTcompatible with Shimano SPD system