Here is a small rear light generally used on MBK 51 and Peugeot 103, it can obviously be installed on other machines. This model has a chrome base and a red cabochon. Its shape under the base is designed so that it is placed on a mudguard.
Please note, it does not have a brake light and is not approved on the road. Delivered as shown in the photograph, without bulb. Clearly, a small lighthouse ideal for tuning your machine but of a fairly low quality. The bulb is not mounted on an anti-vibration support and the cabochon is very fragile.