I've been wondering aboutthe various letters mean in some Simpson bush names. I assumed that an X2 was longer than and X1 but not sure where the L comes in. I have a Colonel X2L a and Commodore X1. The X1 is a pretty short loft and I know that most Commodores are X2 and have more loft than mine. I have never seen a Colonel except the X2L, and many of the Simpson brushes don't have this kind of designation.