You have to email Metroboard and inquire about them. These are “2W” model, there was also a “10W” model which are brighter and longer. These were used on discontinued models so my guess is once stock is exhausted they’ll be gone.
I don’t even run the 2W at full brightness as I only use them as positional lighting so others can see me. I personally run them in series (all 4 LEDs, two per side) at 9.00V which draws 23mA (124mW front + 83mW rear).
An update: the Unity has blown its antispark already after just shy of two months and probably 60 power cycles -ish. (I usually turn it on about once per day, because I have the shutdown timeout set at 5 hours)
Luckily, I wired it with a loopkey from the get-go so there is no repair needed. The power button changed to a power light is the only difference now.