LED voltage question

[Louisbaby]

Hi all

I recently got given a packet containing some tamiya LEDs with a label J15 and J16. Research has shown it attaches to the Multifunction unit made by Tamiya.

I normally make up my own LEDs and tailor them to whatever voltage I might be using, however with these I was wondering if anybody out there knows off hand the voltage used to power these up? The power that comes out of the MFU.

Thanks