I recently bought a 2018 Monster 1200. The previous owner had a custom Underseat Exhaust made for it. It sounds brilliant with the dB killers in, I haven't heard it with them removed... There's been no re-map, and the bike runs and fuels great. It must weigh a good 5kg less than the standard anchor..! He also fitted a Rizoma swingarm mounted Number plate holder that also mounts the indicators. I'm reverting back to standard so this setup is going up for sale. I'm looking for £250 for the exhaust and gubbins... And £200 for the Rizoma mount. I might PX the Rizoma mount for your standard numberplate mount setup. UK postage no problem.