BBR Tuning Billet Carburetor Racing Velocity Stack- 48/66/80cc Compatible with NT and Speed Carburetors The BBR Tuning Billet Carburetor Velocity Stack will give your bike engine a smoother ride, a faster ride, and a sound that can't be beat By increasing the air intake of your carburetor, this velocity stack will give you a better source of air to even out your ride more and give you a boost in power Installation is a breeze: just remove your stock air filter, align the velocity stack choke port over the carburetor's choke port, mount the stack by bolting the stock air filter screws back on to the carburetor, install a new air filter over the stack, a Compatible with NT and Speed bike engine kit carburetors and 48cc & 66/80cc engines Package includes: velocity stack