From Scooter West website
Vintage Vespa Item
This pair of chrome mirrors are super nice-quality chrome. These have 10mm stems and includes nuts (mounting brackets not included). The listed price is for a pair of mirrors.
These mirrors will fit just about any vintage Vespa model, including 1966 Vespa Scooters up to the large frame models, Vespa Rally 200, Vespa P200, Vespa PX and the Stella.
These mirrors are NOT for modern (Automatic) Vespas.
The straight portion of the stem measures 11.25 inches. Including the bend it is 13" to the mounting point. The mirror head measures 4 inches wide. The effective viewing area is 12-16" from the mounting point.
If you have a Stella with a threaded mirror bracket, you will need to buy the "MR-07" brackets separately.