Exhaust Muffler Arrow Thunder Aluminum Black Line KSR Moto TW 125 SM Bj. 15-19

The muffler is 35cm long and weighs about 2.3kg. Thus, in addition to the significantly better sound, he also contributes to the relief of the weight. 
The rear silencer fits on the original manifold and the racing manifold (from Arrow).

This variant is the "Black Line". It simply matches some bike designs better than the "normal" version.

The scope of delivery also includes a clamp and mounting materials.
The Db-killer is secured by a circlip and can be removed for race and test rides, of course ;)

Here you can find the corresponding papers: E13 92R - 01 10371