Calm down - it does not exist.
But imagine having full-strength lume for 12 hours at a stretch.
No, not Indiglo, I mean LUME ON HANDS and INDICES.
Let's say it's Battery powered - and does not drain the battery at all. (Please don't get academic about battery technology. )
You can just switch it on and off.
Would you wanna leave it on all night?
OK, now get excited.