Honda 71-73 CB500 CB500K Piston Kit - 4 Kits - STD Size - 56.0mmHonda 71 73 CB500 CB500K Piston Kit 4 Kits STD Size 56. 0mm New reproduction piston and ring kits. Pistons are cast and replicate original pistons. Includes 4 Pistons STD Size 56. 0mm 4 Rings Sets STD Size 4 Piston Pins 8 Piston Clips Ring Installation Chrome ring on top with "R" up. Beveled black ring is second ring with "R" up. Bottom ring is 3 piece. Be sure not to overlap ends of middle ring. Part # = 13101 323 000 Part Description = PISTON (STD)