Smallest 2x123 that can take a LED drop-in?

[grnamin]

What's the smallest flashlight (legos included, not limited to Surefire) in the 2x123 configuration that can take any of the existing P60-type LED drop-in modules?

 

[Quickbeam]

Vital Gear F2?

http://www.vital-gear.com/

 

[grnamin]

Oh yeah! I completely forgot about the F2. Thank you.