330MM Handmade Stainless Megaphone Silencer. It is all handmade and comes with high-quality internals. The material is stainless steel and it is universal. Plus it has a DB-killer with it, which can be taken out. 

• Material: Stainless Steel
• Length: Approx 330 mm
• Includes a DB-Killer, which can be taken out. 
• Inlet diameter internal : 44 mm or 51 mm (select diameter). You also can use these to make it fit on more sizes!
• Top mount or side mount (select)
• Can be used on both sides of your motorcycle. 

http://www.caferacerwebshop.com/bushing-set-reducer-set.html