I bought this product because my XR250MOTARD was leaking gas from the joint gasket and it was bothering my neighbors. the KITACO product was cheaper, but I wanted to stop the leaking completely and it was highly rated, so I bought this one.
As an advise, you can apply grease to both the inside and outside of the joint gasket with a cheap oil-based product. This will make installation easier, increase efficiency, protect the gasket, and also seal the gasket against gas leaks as the grease will burn off with heat after installation.
The most common mistake is to modify or cut the gasket because it is difficult to fit. It depends on the material.
If you have a Slip-on Silencer, you can use a pliers tool to widen the Silencer side so that the joint gasket can fit. If it is a Slip-on Silencer, you can use Pliers etc. on the Silencer side to widen the joint gasket to fit.
Most of the time, the gasket doesn't fit well on the external silencer side, so the gasket is damaged by forcing it to fit.
The Gas leak stopped completely and I was very happy with Large.