In general:
No. S is suitable for 1.0-1.6 displacement, exhaust pipe diameter 32-43mm < about 78g> No. M is suitable for 1.6-2.0 displacement, exhaust pipe diameter 37-48mm < about 87g> No. L is suitable for 2.0-2.4 displacement, exhaust pipe diameter 44-55mm < about 102g> XL is suitable for more than 2.4 displacement, Exhaust pipe diameter 56-85 mm < about 134g>[Product introduction]
Product name: Car exhaust whistle car whistle throat drum modified imitation turbine pressure relief sound Product color: silver gold black blue purple

Product features: The product is whistle-like sound, suitable for any model, easy to install,
Beautiful and generous, very fashionable, low cost, is the choice to decorate your car.
It's not the sound of a sports car! It's the sound of a siren.
Note: The product is only applicable to the straight exhaust pipe, the bent exhaust pipe cannot be installed