... Material: ZL109 Aluminium Alloy, Alloy cast iron.Piston Type: 1 Steel-insert piston, 2 ALFIN piston , 3 Cast Iron piston , 4 Cooling ... Alfin , No Alfin , Graphite , Oil cooling channel , Sn(tin) plated , Steel Piece , Top Oxidization , Skirt Graphite Printed , Three or Four Ring ...