Feather Of Product 1)Blade:made up of bi-metal (hardness of HRC60- 64degree) with 1.1-1.3mm thickness(From Japan and Switzerland); 2)Clap Arm:7000 series aliuminum alloy;3)Clap tube:aircraft grade 7000 series aliuminum alloy;4)Boot Mounting:165mm/175mm/185mm; 5)Lenght:14";15";16";16.5";17";17.5"; 6)OEM service supplied.