1、The reinforcement of aluminum alloy bracket completely solves the problems of rivet rubbing clamp and strength. 2、Two kinds of materials inside and outside the floating disc are connected by rivets. This connection is not rigid and has a certain amount of free, which reduces the heat transfer. 3、CNC precision manufacturing, high hardness. 4、Stainless steel floating button design, so that the outer dish is not directly locked with the hub, leaving expansion space. 5、2 different colors for you to choose, meet your different needs. Condition: 100% brand new Item type: Bike Floating Disc Material: Aluminum alloy inner frame + stainless steel outer frame Optional Color: black + silver, red + silver Size: Approx. 160mm/6.3in Hole distance: the center distance to the hole is 44mm/1.7in Weight: Approx. 151g Process: CNC engraving and milling, anodizing, stamping forming The floating disc appears to solve the problem that after the continuous friction temperature rise of the integrated disc, the temperature at the center of the disc is different from that at the edge green position due to thermal expansion and contraction, resulting in internal tension. Generally speaking, there are two kinds of materials inside and outside the floating disc, which are connected by rivets. This connection is not rigid. The thermal attenuation is related to the high temperature resistance of the material, and the floating disc will not reduce the thermal attenuation. However, if the disc material and design are optimized and the heat dissipation capacity is strengthened, the anti attenuation ability will be improved. 1 x Mountain Bike Brake Disc 6 x Screw