1. Fitting: for GX390 GX 390 GXV390 13HP<br> 2. PRECISION MACHINED FOR PERFORMANCE Our chainsaw piston ring kit has been carefully designed to deliver performance in your chainsaw. Made from quality materials, this chainsaw piston ring bolt kit ensures precise fit and reliable operation.<br> 3. DURABLE CONSTRUCTION FOR CONTINUOUS USE Our trimmer piston ring pin kit is designed for tough use and is engineered to withstand the tough demands of chainsaw operation. The robust construction of the chainsaw piston kit resists wear and tear and ensures your chainsaw stays in shape even in the most difficult conditions.<br> 4. ENHANCED COMPRESSION FOR MORE PERFORMANCE The chainsaw piston kit improves engine compression, which directly increases the performance and efficiency of your chainsaw. With improved compression, your engine performs the and offers you quieter operation and higher cutting performance.