LED Tail/Brake Light?

[max]

Here's what i use at the moment, works fine but the difference between running and brake light is a bit less than i would have liked, still ok though and should last a fair bit and the light output is fine;

Things to watch out for is the dual contacts in the base and the wattage.
Designations are bay15 s ( single contact 15 mm socket ) and bay15d ( Double contact ).

I think bay stands for Bajonet socket Automotive And i give up on the y bit, could be a size unit for the socket.

You want the bay15D variety like in this picture.



just got some spares for the future too.