They call it LRS (s for short I suppose).
Where the LR is about the size of their 3C ML50 the LRS is about the size of their 2 cell ML50.
In side by side you do see more throw from the longer one but that 850 lumen LRS packs quite a punch through darkness. The replacement battery cost is a lot higher for the short one for some reason.
If you don't keep it on charge and don't use it for a few months at a time be sure and loosen the tail cap a bit or it will self discharge below a point where the charger won't charge it back up. I found that out after the 1 year warranty had expired.
The light would turn on briefly but shut off in like 2 seconds. So I contacted Maglite about it. They said I could send it in to evaluate but I just opted to buy a new battery, which solved the issue. Those electronic switches they use these days are vampires. But about a half turn of the tail cap loose works to keep it from discharging.