2.677" bore X .640 compression height X .490 wrist pin 3 Ring Wiseco Piston with rings and clips, no wrist pin. Same quality you have come to expect from Wiseco forged small engine pistons now available in a three ring version for better ring seal. Light weight forgings designed for maximum strength and dependability. Internal micro-penned finish that reduces possible stress fractures. Use wrist pin # 6521 sold separately.