Good material ---- This muffler insert is made of iron, which is of high hardness. So it's very durable for db killer 45mm Good material ---- This muffler insert is made of iron, which is of high hardness. So it is very durable for db killer 45mm Multiple Choices----These items are suitable for tail exhaust pipe diameter size of 35mm/42mm/45mm, and you choose from three diameter measurements. You can choose the right Environmentally friendly ---- Environmentally friendly can effectively reduce noise, on the other hand, it can also reduce noise contamination, which is environmentally friendly of the environment. Working principle ---- Using a muffler near the end of the vehicle exhaust system, its working principle is destructive interference and absorption. The muffler wall is made of two layers of stainless steel, which helps reduce vibration and absorb sound Features----Easy installation, adjustable and removable Features: 1. Removable universal silencer. 2. Can effectively reduce the sound of deep notes, also reduce sound contamination. 3. Metal construction, very durable. 4. Easy installation, adjustable and removable. 5. Fit for tail exhaust pipe diameter size of 35mm/42mm/45mm. Features: Color: Silver Material: Metal Package Weight: Approx. 112 g Optional base diameter (millimeter): 35mm / 42mm / 45mm Optional diameter (inches): 1.38 "/ 1.65" / 1.77" Total Length: Approx. 135mm / 5.31" Thread: Approx. 6mm / 0.24" Package Included: 1 x Silencer Note: 1. Please allow 1-3mm error due to manual measurement. Thanks for your understanding. 2.Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object.Please take the real one as standard. 3. No Instruction Included.Professional Installation Is Highly Recommended. 4.Please Check The Size Measurement Chart Carefully Before Making Payment.