The BBR Tuning Front and Back two stroke gas bike engine mount vibration reducer is designed to control the engine vibration to supporting structures or frames. These isolators increase operator comfort and protect other equipment components from premature failure due to vibration. When properly engineered, these types of mounts can prevent as much as 75-85 percent of the engine vibration from being transmitted. These mounts do NOT work with the Dragon Fire Engine Kits or 4-stroke motor mounting plates. These mounts will help prevent broken studs in your engine and help keep it secure. The BBR Tuning Front and Back two stroke gas bike engine mount vibration reducer is designed to control the engine vibration to supporting structures or frames. These isolators increase operator comfort and protect other equipment components from premature failure due to vibration. When properly engineered, these types of mounts can prevent as much as 75-85 percent of the engine vibration from being transmitted. These mounts do NOT work with the Dragon Fire Engine Kits or 4-stroke motor mounting plates. These mounts will help prevent broken studs in your engine and help keep it secure. Specification 1 Front Support 2"x1"x1.5" 1 Back Support 2"x1"x1.5" 4 Motor Screws 4.5" M6X1.0 4 Lock Nuts 4 Washers 4 Lock Washers