Looking for a replacement piston for your 108FSR BX-1 engine? Look no further than this genuine O.S. piston. Made to fit perfectly with your engine, this piston is designed to deliver optimal performance. Compatible with O.S. engines, this piston is a must-have for any RC vehicle enthusiast. Don't settle for anything less than the best when it comes to your engine parts. Trust in the quality of O.S. and enjoy a smooth and powerful ride.