[Elecraft] BL1 vs. BL2 Balun

[Strode, Carl R]

Aside from the switch to change from a 1:1 to 4:1, what are the
differences between the BL1 and BL2? 

I've never seen either, however it appears to me that the BL2 has two
binocular cores, and the BL1 has a single core.  Is this so? 

By the way - does anyone know the specs on the core (dimensions, type,
etc)? 

I'm guessing it is a mix 43. 

Carl 
WA7CS 

Please accept my apologies if this is a duplicate post - there seems to
be some problem with the list accepting my input (I've got the same
problem here at the office with my Boss :-)