Saying a Jet-III Pro Ultra isn't much bigger than a Jet-III Pro ST is like saying a Fenix TK11 isn't much bigger than a Fenix P3D. There's a definitive difference in size and handling between the two lights. The OP said he was looking for the shortest possible 18650 light without any giant reflectors or attack bezels which is why I recommended the Jet-III Pro ST. But it appears maybe the OP changed his mind as he's considering a Fenix TK11 so I guess the point is moot now? In that case might as well throw in all the other "tactical" style lights for consideration like the Eagletac T10L, Dereelight CL1H, Olight M20, etc.