Here we have for your YZF-R 125 a clear glass tail light with E-number. Because of the E-number, which is directly cast into the clear glass, you have no problems with the TÜV or a control, because you can use the tail light EU-wide.
The connection is very easy. You only have to remove the small rear part underneath the pillion seat of your Yamaha YZF-R 125 and then you can already see two 10mm nuts holding the original tail light. Also the electrical connection does not require any previous knowledge, because the plug is exactly the same as the original plug.