... 3. Meet-your-needs packing NPR RIK piston ringA: 8PE1 engine piston ring1. Piston ring Material : Cast iron , Alloy , Steel2. Piston ring Feature : 1 Chrome ... Steel-insert piston , 2 ALFIN piston , 3 Cast Iron piston , 4 Cooling channel piston , 5 One piece casting piston , 6 Compages piston , 7 Forged piston piston, 8 Two ...