O.S. tuned silencer (Tuned Pipe) specifically designed for the OS Max 140 RX 2-Cycle airplane engine is constructed of aluminum. Mounting hardware included. This product includes one tuned pipe. One silicone connector. Two coupler clamps. One tuned pipe mounting bracket. Three 3x15mm allen head machined screws. Three 3x10mm allen head machined screws. Six 3mm silver nuts. One instruction sheet.