This is a complete turn signal assembly, supplied with the base, housing, reflector and lens. These parts are only available individually from BMW and if you were to each piece, it would add up to more than the price of this entire assembly.
This turn signal is made by CEV, the original equipment manufacturer, so it is identical to the original and not a reproduction.
This is what we consider the short version because of the length of the stalk (holder) and it fits the rear of many models. These can in some cases also be fitted to the front. Note: If you want to fit these signals to the front, then order the opposite side so that the drain hole will be on the bottom. (example: a right rear will also fit a left front)
Please compare the picture to your bike to be sure that you are ordering the correct replacement.
Overall Length from flat of base to tip of turn signal = 10.5cm (4")
Height of stalk (not including locating pin)=15mm (5/8")
Please note the shape of the stalk and compare it to what is on your bike. Some of the original stalks are offset. If that's what you have, you can a) replace both left and right assemblies so that they will match b) re-use your original stalk if it's not broken.